Also many bench supplies have very large output capacitors. I have a smaller HP on my bench and recorded over 100 amps instantaneous on a short with a couple feet of #10 leads. That was all from the output cap, it¡¯s a 10 amp supply.?
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On Aug 20, 2018, at 2:18 PM, george edmonds via Groups.Io <
G6HIG@...> wrote:
Hi
In my experience most bench power supplies show a similar behaviour. ?At one time I suffered repeated damage to equipment that was powered from a bench supply, when checked with a storage scope it went to a high voltage on turn on before settling back to the set voltage.
I still think that for valid measurements you cannot use a light bulb, they are NOT a linear devices if you do an applied voltage plot against observed resistance, from a sixtey year old memory of an experiment they are square law devices
73 George G6HIG ??
I refined my test...
Instead of ramping the voltage with the knob. I basically set the voltage to 20V and the amperage to 2 amps. I connected the voltmeter in series with the bulb and performed a dynamic load test by opening and closing the circuit by touching the probe lead of the voltmeter to the output of the power supply... I also have the Fluke voltmeter set to peak amperage measurement and these are the results that I found.
With the 6012B set to 20V and 2A, upon closing the circuit the peak amps are 4 amps but quickly settles to 2 amps
With the 6024A set to 20V and 2 A, upon closing the circuit the peaks amps are about 2.5 but quickly settles to 2 amps.
The important observation here is the 6012B settles back to 2 amps, it seems the settle time is longer and the deviation is larger than the 6024A. Although these are two completely different supplies. If anything I could be nit picking here on the 6012B for its regulation settle time and overshoot, which is why I wanted to see if someone else had a similar supply and could see if they could duplicate the same results to see if this is normal...
Thanks for the help
