Author Topic: Classic 2 slow flash behind grill  (Read 1156 times)

boB

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Re: Classic 2 slow flash behind grill
« Reply #45 on: February 03, 2019, 01:22:06 AM »
It took me a long time to figure out what's going on here. The pulses look like they vary in frequency while maintaining a 50% duty cycle. I don't care about the frequency but the PWMs I've worked with all change the duty cycle.

Simply changing the Fq will only create internal heating /switching losses, which will subtract from the delivered power

Yep.  That would be a pretty bad way to use extra power !

It's actually PWM control, not frequency at a fixed Duty
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DEinME

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Re: Classic 2 slow flash behind grill
« Reply #46 on: February 09, 2019, 08:01:31 AM »
It took me a long time to figure out what's going on here. The pulses look like they vary in frequency while maintaining a 50% duty cycle. I don't care about the frequency but the PWMs I've worked with all change the duty cycle.

Simply changing the Fq will only create internal heating /switching losses, which will subtract from the delivered power

Yep.  That would be a pretty bad way to use extra power !

It's actually PWM control, not frequency at a fixed Duty

In that same graph (diagram 5, p. 43 of Rev H), in the top curve there is a "width (in volts)". How are these volts set.

I believe the Y axis is battery volts. I'm going to guess that the top dotted line is the charge setpoint and the bottom line is the setpoint from the AUX selection.  (?) I.e. if I'm using Waste Not Hi with -0.2V and the charge controller is in absorb at 59V, then the top line would be 59V and the bottom line would be 58.8V. (??)

Thanks.

PS I'm going to fit my browsing into some weekday instead of bugging youse on weekends.

Edit to add: found the width parameter on a config screen for WasteNot
« Last Edit: February 17, 2019, 08:58:19 AM by DEinME »
4800W PV in 2 circuits of 96V & 50A each after the Midnight combiner. Two Midnight Classic 200. MagnaSine 4448 split phase inverter on a Midnight e-panel. 700Ah or 900Ah FLA @ 48V. Birdhouse,WBjr, etc. Replaces 16-year-old off-grid full-time 408W PV & 300W Morningstar inverter.