I have one of Caswell's 3A and a 20A CC/CV rectifiers right now. I will get to measuring them shortly. Are you still using these for very low voltages and low currents? Can you give me some voltage and current numbers where his problem occurs?
You can easily confirm the voltage readings on the power supply read outs. Measure across the PS outputs with a multimeter and see if they agree. The readouts can be adjusted (?) by a pot internal to the unit if the reading is off. But not the "threshold" to start up, this in inherent in the design.
If you read the User's Manual that came with the PS, under "Technical Parameters" you will see that the manufacturer won't sign up to any regulation below 6 mV (0.006 Volts) or any current below 3 mA (0.003 Amps) they say nothing about startup at very low settings. The readouts can also be as much as "2 digits" off". What they're trying to say in Chinese English is that the right-most digit could read a "3" when the real number is "1". In other words, off by 0.02 Amps or 0.2 Volts maximum.
Mike Caswell has told me that you are the first and still the only one experiencing this problem. I'd like to know more about exactly what you are doing.
The better way is a real laboratory grade CC/CV power supply. Go check the prices on these, you'll see. What you have really is seriously inexpensive, actually dirt cheap compared to the alternatives.
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