I will try to explain my simple voltage clamp and how it operates. It requires 2 components a simple ice cube relay with a 12vdc coil and 120vac contacts and a 3 phase magnetic contactor rated for the max current the turbine is capable of that has a 120vac coil.
We start with a 12 volt dc signal from the Classic that is always there until the input voltage goes above a user set value. (I believe this mode will be something like PV Trigger. This feature is being done as we speak we currently use a voltage monitoring relay but it is not necessary with the Classic)
The 12vdc then feeds into the coil of a simple relay with a 12vdc coil and 120vac contacts.
Then we take 120vac from the inverter fed panel and feed it through the NC contacts of the above relay and into the coil of a 3 phase definite purpose contactor sized accordingly for the turbine we are stopping.
We then take the 3 phase ac from the turbine in parallel with the rectifier and feed that into one side of the contactor and we run short jumpers on the other side to short the 3 terminals.
The theory of operation is that the Classic will always have 12 volts out holding the relay open. When in the open state the relay will not pass ac through because we used the NC contacts. As soon as the Classic sees an input voltage of the user set point it removes the 12vdc thus passing ac on to the 3 phase contactor shorting out the turbine and stopping it. The reason I prefer this way is simply so if something happens to the Classic be it a breaker tripped or what have you the turbine stops.
Care must be used with this simple clamp to make sure the turbine you have can:
A-Stop without damage to the turbine when shorted at high speeds.
B-Actually stop when shorted for example a Bergey XL1 will not stop when shorted and I would worry this would burn the stator out.
I believe one could calculate the correct value of resistors to use instead of a hard short and it would be a little more delicate on the turbine but our otherpower style turbines do not seem to mind being stopped like this. I also believe we could program the Classic to latch and unlatch semi fast to kind of bump the voltage down a little milder for turbines that can not be stopped like the XL1 boB and I have to discuss this further
Here is a link to the Diagram http://www.midnitesolar.com/pdfs/Ryans%20Clipper_Diagram_11-24-2010.pdf (http://www.midnitesolar.com/pdfs/Ryans%20Clipper_Diagram_11-24-2010.pdf)
Ryan
Thanks for this info Ryan. I've been wondering how I could set up a homemade Clipper to work along with a Classic on my wind turbine. I've got a Windmax HY-2000 2kW 48V wind turbine that I've seen crank out over 3kW during wind gusts in the 30mph range.
Your voltage clamp uses a 120vac contactor.
Do you know if they make 3 pole contactors that can utilize 48vdc on the coils?
I do not run an inverter normally (unless grid power is down). I divert power to an auxillary hot water heater. I am on-grid and I could get 120vac from the grid, but the thing that makes me nervous is that during very high winds, the grid power can go down. Then again, maybe it would be fine as I think you said the contactor would be NC.
I do not like the idea of abruptly shorting the wind turbine in high winds speeds, because I am concerned that doing so could create a surge/spike that could burn out stator windings. I had something like this happen in the past on a different 2kW wind turbine. It happened during strong winds and I went to shut it down with a 3 pole switch that I set up to short out the turbine. Upon flipping the switch, I had a runaway turbine that was out of control. It melted down internally before it threw a blade - thank God! It was ruined. I do not want to experience that again! So, I like your idea of dumping 3 phase output to resistors to slow the turbine. In fact, my HY-2000 controller system came with a 3 phase dump load (resistor heater box) that I could use.
Would the 12vdc signal from the Classic allow the contactor to release the "brake" and turn the turbine back on once the voltage dropped?
Would there be any way for the Classic to also attempt to brake the wind turbine if a certain RPM was exceeded?
I know from the factory that my wind turbine is supposed to be safe up to 800RPM. So, let's say I want to be safe and limite max RPM to around 700RPM. Just wondering if there is a way I could do this with the Classic and a homemade voltage clamp.
Edward
You probably can find a contactor with a dc coil I would rather see that myself as it does not depend on the inverter/grid. You could experiment with resistors on the other side of the contactor to make it a soft stop device. The Classic wont limit based on rpms that is where our Clippers will come in.
Ryan wrote: "I also believe we could program the Classic to latch and unlatch semi fast to kind of bump the voltage down a little milder for turbines that can not be stopped like the XL1"
Something like that sounds good. If there was a solid state contactor, then the frequency of the latching/unlatching could probably be higher. If there are no 3 pole solid state contactors available, then I wonder if 3 Solid State Relays could be set up.
I'm also thinking that I could get the RPM braking I want indirectly (based on the voltage). Not only would the voltage set point be to protect the Classic, but I suspect it could also be set at a level that would equate to a safe turbine RPM. Since I don't have tail furling, my turbine is always facing into the wind. As wind speed increase, turbine RPM increases, and voltage output increases. It should all track fairly closely and predictably. Based on the "Power vs RPM" and "Power vs Wind Speed", I wonder if I could set the RPM limit indirectly based on voltage level. I am on-grid. My system is set up so that my battery bank is normally fully charged and in float mode for emergency backup, and I divert excess power with a Coleman Air controller to a auxillary hot water heater. So, system voltages (on the battery side) stay fairly constant. Perhaps I could calculate a voltage that would correlate to turbine RPM and use that as my RPM limit brake. Assuming that this would also fall below the safe voltage limit of the Classic I chose (150, 200, 250), then that voltage set point might be able to serve both to protect the Classic and also my wind turbine from excessive RPM's. Not sure, and I'm "thinking out loud" here.
In case it is pertinent to the discussion, here are some pictures showing my wind turbine set up and how I divert excess power off the battery bank and heat hot water.
http://www.facebook.com/album.php?aid=31445&id=100000264867099&l=6c791ef013 (http://www.facebook.com/album.php?aid=31445&id=100000264867099&l=6c791ef013)
Edward
Quote from: Halfcrazy on December 02, 2010, 05:49:19 AM
You probably can find a contactor with a dc coil I would rather see that myself as it does not depend on the inverter/grid. You could experiment with resistors on the other side of the contactor to make it a soft stop device. The Classic wont limit based on rpms that is where our Clippers will come in.
UNLESS.... Unless the turbine is free-running... Then you could equate RPM to Voltage and just limit
on Voltage = RPM = Wind speed. ( if you can get the date to correlate those 3 things)
boB
That's what I was thinking Bob. Based on the data on my turbine, I am wondering if I could come up with a voltage limit that would correlate to RPM.
(http://www.key-ideas.com/HY-2000-Power-Wind.jpg)
(http://www.key-ideas.com/HY-2000-Power-RPM.jpg)
The trick is trying to come up with a correlation of how voltage varies with RPM on this turbine. I've asked the manufacturer about this data, but they might not have understood what I was asking. Not sure if they would have ever tested the wind turbine without their controller attached which clamps voltage to a max of 60VDC (dump point on their controller). They might not even have this data.
Edward
OK. I'm still seriously considering the Classic for my wind turbine, but I am waiting for them to be released to the general public and see what other people think once more people have tried them with wind. In the meanwhile, I'm still keeping the Classic open as a top option. I have 3 other ideas as well which include 2 existing wind turbine controllers that I currently own. My main motivation in using the Clipper would be to have a more reliable turbine. In part, by running higher stator voltages (less heating and less chance of stator meltdown). Secondarily, I'd like to benefit from more efficient power production with the MPPT.
Keeping my Classic option open, I've been searching around for a 48VDC coil contactor to use with Ryan's idea of a homemade "Clipper". I got one on eBay for $10 + around $20 shipping. AMP ratings seem to be fine with 65A intermittent and 45A continuous. Once the contactor connects, the current should drop quickly as the shorted turbine slows to a near standstill, or if I slow it way down with heating resistor elements.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rt=nc&nma=true&item=260704354161&si=ca3brfW4OhtvEZcEpoP4OljY9Gk%253D&viewitem= (http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rt=nc&nma=true&item=260704354161&si=ca3brfW4OhtvEZcEpoP4OljY9Gk%253D&viewitem=)
Ryan, does this look like a contactor that would work with your idea of a homemade voltage clamp?
Have you and Bob done any more work with the 12V Classic output that could be "pulsed" to control a relay that would control the contactor?
Happy New Year!
I was thinking about Ryan's homemade "Clipper" (voltage clamp). Found these 3 phase Crydom Solid State contactors and the specs look good for possible Classic use. They offer DC control versions with power handling capability of 50A per leg (Crydom P/N D53TP50DP).
(http://www.crydom.com/en/Products/Catalog/PicturesCategory/D53TP25.jpg)
Looks like control power could come directly from the Clipper's aux relay output. Crydom spec sheet lists control voltage of 3-32VDC and control current rated at a measley 10mA @ 5VDC. So, it appears that the Clipper could easily control this directly, with no need for an intermediate relay. Since it's solid state, then perhaps the Clipper could use a higher frequency pulse to apply "softer" braking to the turbine. I found pricing on these at $99 online, so they are not unreasonably priced. A heat sink would also be needed, but that would be simple and relatively inexpensive to come up with as well.
Here are the full specs on these Crydom 3 phase SSRs.
http://www.crydom.com/en/Products/Catalog/5_3tp.pdf (http://www.crydom.com/en/Products/Catalog/5_3tp.pdf)
Looks like these might be a good match for the Classic.
Edward
Quote from: keyturbocars on January 01, 2011, 10:51:11 AM
Happy New Year!
I was thinking about Ryan's homemade "Clipper" (voltage clamp). Found these 3 phase Crydom Solid State contactors and the specs look good for possible Classic use. They offer DC control versions with power handling capability of 50A per leg (Crydom P/N D53TP50DP).
(http://www.crydom.com/en/Products/Catalog/PicturesCategory/D53TP25.jpg)
Looks like control power could come directly from the Clipper's aux relay output. Crydom spec sheet lists control voltage of 3-32VDC and control current rated at a measley 10mA @ 5VDC. So, it appears that the Clipper could easily control this directly, with no need for an intermediate relay. Since it's solid state, then perhaps the Clipper could use a higher frequency pulse to apply "softer" braking to the turbine. I found pricing on these at $99 online, so they are not unreasonably priced. A heat sink would also be needed, but that would be simple and relatively inexpensive to come up with as well.
Here are the full specs on these Crydom 3 phase SSRs.
http://www.crydom.com/en/Products/Catalog/5_3tp.pdf (http://www.crydom.com/en/Products/Catalog/5_3tp.pdf)
Looks like these might be a good match for the Classic.
Edward
Thanks Edward ! We will have to get one of these and check it out.
It might just work in a lot of situations ! Certainly worth a try.
boB
boB,
The specs look promising. Hopefully, they pan out in real life. I'm thinking of picking one up myself to have on hand for experimentation. I already have an ABB 3 pole contactor with 48vdc coil that I picked up, but I'm not really excited about a mechanical relay. I'm interested in doing something like Ryan showed with the Classic's aux relay output, but I like the idea of being able to "pulse" the brake with a SSR to get a "softer" braking effect.
At this point, I'm just not sure if 1 or 2 Classics would be required for my turbine. I think Robin mentioned that there might be a Classic beta tester that has a Windmax HY-2000 turbine. I'm looking forward to see how many Classics will be needed to handle this particular turbine.
Fun stuff!
Edward
In case this will be of help to someone in the future, I'll add this to the thread...
For bigger turbines, I ran across some 3 phase solid state relays that can handle up to 90A per leg. These are made by Powersem (German company) and they offer 25A, 50, 75A, & 90A versions.
http://www.powersem.net/range35.php (http://www.powersem.net/range35.php)
Not sure of all US dealers for Powersem, but they can be ordered here:
http://www.semimart.net/shop/index.php?cat=c43_Solid-State-Relays.html (http://www.semimart.net/shop/index.php?cat=c43_Solid-State-Relays.html)
The 90A per leg 3 phase SSR is not cheap at $200, but it can handle a lot of power.
Edward
I'm also going to throw this thought out there in this thread. I haven't yet tried the SSR relay, but I had something come to mind yesterday that got my attention. One of the specs on these SSR relays finally sunk through my thick skull and brought up a question in my mind.
The Crydom and Powersem 3 phase SSR's have the following voltage specs:
Crydom: 48-530Vrms
Powersem: 100-660Vrms
Now, the way that I plan to use the SSR, things might be OK. I plan to use the 3 phase heating elements that came as the dump load for my HY-2000 wind turbine. So, when the Classic energizes the aux relay output, the SSR would dump 3 phase wind turbine power to the heating elements.
BUT, here's where I have a question....
For those that plan to utilize a crowbar type brake, when the SSR is triggered and the 3 phases are abruptly shorted out, then the voltage would drop to 0.
Won't that cause the SSR to malfunction because it is relying on some Vrms in order to function properly???
That's the big question that comes to my mind. There's a reason why they don't spec those SSR's with 0-XXX Vrms. They must not function properly below that lower limit.
In the case of dumping 3 phase power to a heating load, then if the wind turbine slows to the point that the voltage drops below the lower limit, then perhaps the SSR would also malfunction. I'm not sure. It's one of those things that would need to be tested in real life, I suppose.
Just throwing this out there as a possible monkey wrench to the SSR idea. Of course, a standard 3 phase electromechanical relay/contactor should still work fine as Ryan has tested. I already picked up one of those, but liked the SSR idea better, so that's why I went off investigating that route. Perhaps the SSR idea still might work if the Classic applies "softer" braking, so the turbine doesn't slow to the point that the Vrms drops too low.
Just food for thought.
Edward
Quote from: keyturbocars on January 10, 2011, 07:20:23 PM
It's one of those things that would need to be tested in real life, I suppose.
Edward
We will be buying a couple of these and trying them out, Edward. Hopefully very soon !
boB
I suspect these relays like any other would have a coil voltage to activate them which would be a 12 vdc source from the Classic the 3 phase ac should not have any bearing on that. Just looked at them and they do have a coil to activate them so this would be a non issue as long as you can get the coil in 12vdc.
Not sure how these work beyond 60hz or so, or if AC-DC rectification has been done previously, and these will be switching DC instead of 3 or more phase wild AC.
This SSR would be wired "upstream" of the rectifier and would be controlling 3 phase wild AC. The Classic would be monitoring the DC voltage level, and when the voltage reaches a limit set to protect the Classic, the aux relay output would send a control signal to the SSR. The SSR relay would effectively dump the 3 phase output or short it out to slow (brake) the turbine. This is a great idea that Ryan presented for a homemade Clipper.
Edward
Quote from: keyturbocars on January 11, 2011, 04:55:51 PM
This SSR would be wired "upstream" of the rectifier and would be controlling 3 phase wild AC. The Classic would be monitoring the DC voltage level, and when the voltage reaches a limit set to protect the Classic, the aux relay output would send a control signal to the SSR. The SSR relay would effectively dump the 3 phase output or short it out to slow (brake) the turbine. This is a great idea that Ryan presented for a homemade Clipper.
Edward
Better check on how the SSR works with >120 hz wild AC. What's the freq when it's really spinning in the wind? 300Hz ? 700Hz At >120Hz, the relay may work "differently" .
Quote from: mike90045 on January 12, 2011, 03:50:54 PM
Quote from: keyturbocars on January 11, 2011, 04:55:51 PM
This SSR would be wired "upstream" of the rectifier and would be controlling 3 phase wild AC. The Classic would be monitoring the DC voltage level, and when the voltage reaches a limit set to protect the Classic, the aux relay output would send a control signal to the SSR. The SSR relay would effectively dump the 3 phase output or short it out to slow (brake) the turbine. This is a great idea that Ryan presented for a homemade Clipper.
Edward
Better check on how the SSR works with >120 hz wild AC. What's the freq when it's really spinning in the wind? 300Hz ? 700Hz At >120Hz, the relay may work "differently" .
Yeah, we certainly don't want the relay buzzing around at high frequencies, so the software tries not to allow that for that particular aux output (Aux 1)
The Classic has two (2) Aux outputs. The one with the Relay can be jumpered to put out a 12V "signal" or can be the relay contacts themselves... VERY low current contacts though, like, 1/2 Amp max. This Aux 1 output is basically a slow aux output with an adjustable Delay and Hold time, , adjustable in 0.1 second increments. and High and Low ON and OFF thresholds, adjustable in 0.1 Volt increments.
Aux 2 diversion output is a few hundred Hz PWM 12V signal that can be triggered from Classic input voltage or battery voltage and operates over an adjustable voltage window, from 1V to about 5 Volts. The smaller the window, the higher the PWM frequency, or about 500 Hz maximum.
If what we are all calling a SSR Solid State Relay is a thyristor, (Triac or SCR), (light dimmer switch), then it turns on when you tell it to, (as long as there is some current available), and turns off automatically at an AC zero crossing. In the case of a wind turbine, yeah, it can be several hundred Hz. They seem to work just fine at these frequencies as far as I have seen.
If thyristors are being used, I would say that Aux 1 might be the one to use. Either Aux operates on average voltage.... It's not very slow, but will take a quick moment to change its reference point. I will try and add a peak/average select for this if it works out better.
There will be more about this in the manual and online.
boB
Sounds good boB!
boB,
In the back of my mind, I've been chewing on what you wrote about Aux 1 and Aux 2. Today, I had an idea pop in my head. If I am understanding this right, then I think this might work...
AUX 1 - Wire to a Crydom D53TP50D 3 phase SSR to divert 3 phase AC power to 3 phase dump load heater box that came with my HY-2000 wind turbine. I plan to set the divert voltage to around 125VDC. This would act as a brake for my turbine and a voltage clamp to protect my Classic 150.
(http://www.crydom.com/en/Products/Catalog/PicturesCategory/D53TP25.jpg)
AUX 2 - Wire in a Crydom D1D100 single pole DC SSR (MOSFET) that would monitor battery voltage and control the diversion load to my hot water heater. The Crydom D1D100 SSR is a MOSFET design and is designed to handle up to 100A continuous and up to 100VDC. I would set up the diversion right off my 48V battery bank. Then I can eliminate the Coleman Air controller from my hot water heating system.
(http://www.crydom.com/en/Products/Catalog/PicturesCategory/1-dc_photo.jpg)
Here's the spec sheet on that Crydom D1D100 100AMP 100VDC DC SSR:
http://www.crydom.com/en/Products/Catalog/d_1_d.pdf (http://www.crydom.com/en/Products/Catalog/d_1_d.pdf)
I would wire that Crydom DC SSR so that the control voltage circuit is in series with my water heater thermostat. If the hot water heater hits 125F, then the water heater diversion shuts off that DC SSR. This will very rarely happen in my household of 9 with lots of hot water use. For those rare situations, then I'd plan to use my existing Coleman Air diversion controller set to a higher voltage trip point as an emergency backup diversion. I already have a couple big 2kW load resistors (the big green type) that I can set up for a 4kW diversion as the emergency backup.
To summarize my rambling, I would have it set up with AUX 1 controlling my AC diversion to the 3 phase heater box. The AUX 2 PWM output could "buzz" the Crydom DC MOSFET SSR to control my hot water heater diversion to keep my AGM battery bank at the recommended 53.2V float voltage. As an emergency back up diversion load, I'd have the Coleman Air diversion set up to 4kW air heating resistor.
If I could get rid of the Coleman Air diversion controller as my hot water heating controller, that would be great! I have a hard time getting it to keep my battery bank at the float voltage I want, because it's operation is so crude with 5 second sample rate. My battery bank is just for emergency back up power, and it normally just needs to be kept in float mode.
Does this make any sense? Am I understanding (at least a little) the way that AUX 1 and AUX 2 on the Classic could work, and does this sound like it could work?
Just tell me if I am full of hot air and confused beyond all hope! It wouldn't be the first time! :)
Edward
Quote from: keyturbocars on January 16, 2011, 01:58:43 AM
boB,
The AUX 2 PWM output could "buzz" the Crydom DC MOSFET SSR....
Just tell me if I am full of hot air and confused beyond all hope! It wouldn't be the first time! :)
Edward
No, I don't think you are full of hot air, but you might be full of hot water pretty soon ! BTW, why does everybody want to heat hot water ?? Don't they want to heat cold water ?
I believe that what you are talking about doing is just fine and appropriate for those particular SSRs...
I think the 125V 3-phase portion is good because it is driven off the "slow" non-pwm (non-buzzing) diversion and will be set to divert when the PV input voltage rises above 125 Volts DC and you can set the LOW voltage to turn off somewhere below, say, 123 VDC. This is appropriate for an SCR or Triac type of SSR, too, especially running the turbine into a load like what you are describing for the HY-2000.
Aux 2... I like your use of the word "BUZZ".... I think that could be a great "Buzz word" for the hundreds of Hz PWM used in Aux 2. And a FET type of SSR for the DC side should be perfect here.
You can set the diversion threshold V to either be absolute, (pick a voltage), or a voltage relative to the particular charge stage the system is in at the moment... (Absorb, EQ, Float) This diversion mode can be adjusted to start diverting (Pulsing or "Buzzing") at (0.0) or above / below the present battery set point voltage (absorb, float, EQ). You most likely will want to adjust it slightly below the setpoint voltage.... For example, -0.3 Volts. There is also a voltage "width" adjustment, the voltage width being the range where the PWM goes from a short pulse, beginning right at the charge setpoint voltage, and full on at the diversion set point voltage "plus" the width voltage. For example, if the Controller is presently Absorbing (voltage regulating) at 14.5 Volts and the Aux 2 Relative threshold voltage is set for -0.3 Volts, the Aux 2 diversion PWM pulsing or "buzzing" will start to become ACTIVE when the battery reaches 0.3 Volts below 14.5 volts.... (14.2 Volts and if the Width adjustment is at 1.0 Volts)... The Aux 2 diversion output would be fully Active (not pulsing anymore) at 14.3 V ~PLUS~ 1.0 Volt or, 15.3 Volts. This voltage width gives the PWM diversion function some "room" for the SSR and loads to work. How much of that voltage width is actually used depends on the value of the load resistance, (your water heater), and the amount of power available from the source (PV or turbine) If the diversion load resistance is not low enough, it will not be able to load down the battery enough and will more likely approach the full voltage width.... The higher the diversion load is, (lower resistance), the less width will be used. This leaves some room for more available power to be diverted. However, the diversion load resistance doesn't want to be TOO low, or the diversion operation won't work quite as smoothly as it would if it has SOME room to move about.
Aux 1 diversion mode is similar to Aux 2 diversion mode except that it does not PWM, Pulse or buzz at hundreds of Hz rate. Instead, Aux 1 diversion goes Active at or above the "High" voltage setting, after a programmable "Delay" time, and goes Inactive when the voltage drops below the "Low" voltage setting after a programmable "Hold" time. These Delay (or Attack) and Hold times are adjustable in 0.1 Volt increments.
The Aux Relative Voltage adjustments are referenced to the temperature compensated Absorb, Float or EQ voltage. In the Classic, the EQ regulation voltage can be chosen to be either battery temperature compensated or not. This choice is picked in the Charge -- Temp-Comp menu.
In battery relative diversion mode, when either Aux outputs go "active", either solidly for Aux 1 or pulsed for Aux 2, you can choose to keep the charge timers and counters running (or not) for the Absorb and EQ stages so that the controller will go to Float when that charge stage is finished (its timer has expired). This could be important, because the diversion might be holding the battery voltage below the desired set point voltage for that charge stage. As long as the Relative diversion threshold voltage and absolute Absorb, Float and EQ voltages (charge menu) are chosen with some degree of thought, using the diversion in concert with the normal "raising the input power source voltage" method to regulate battery voltage, can work very well for battery charging cycles. You might want to set the absolute a few tenths of a volt higher than usual so that the diversion mode can be used to greater benefit. This will help to ensure that if the diversion loads go away, the battery voltage won't go TOO much higher than desired and battery over-gassing would be minimal. Using diversion in this way is what we call "Use It Or Lose It" mode (Ui-Loi)... Just think of the song, "Louie-Louie".
For Relative diversion using Aux 1 or Aux 2, the default to keep the charge timers running will be enabled.
Aux 1 and Aux 2 outputs can also be chosen to be "Active High" or "Active Low"... Active "High" is the normal mode of operation and means that the Aux output will be at 0 Volts (ground) when Off and 12 Volts when On... Low, being 0 volts and High being 12 volts. Active High is shown in the Aux menus with a "+" sign following the mode name and Active LOW mode with a "-" following the name. The output voltage for a High is actually more like 14 or 15 Volts DC and can supply up to 200 milli-Amps of current.
Aux 1 also has a (small) relay that can be jumpered into the circuit if an isolated switch is needed. This might be used to start or stop a generator. Remember though that this is a very small relay with 1 Amp rating and a series 1/2 Amp resettable fuse in series with it to help protect its contacts.
boB
Quote from: boB on January 16, 2011, 05:28:45 PM
BTW, why does everybody want to heat hot water ?? Don't they want to heat cold water ?
Good point! ;D
Thanks for all the great info boB!! My brain will be feasting on this information. No doubt I'll read it through more than once, so I can digest it all. I'm finally ready to start ordering parts... including one of those rare Classics made of unobtanium! :)
Amazing what the Classic can do!! It's definitely smarter than I am!
Edward