If you read my previous blog, you will see that I found that the D3806 power module produced large over-voltage spikes on its output terminals when you switch on the DC supply to it (even if it's output was programmed to be off on power-up). This could send a surge of up to 10V for approx 10 mS into your nice little 3.3V arduino and blow it up! It also sent spikes when you switched it off too!
I had planned to use this device together with an old ATX power supply to make a nice variable, current-limited bench power supply.
So I decided to try to work around this issue and I designed a delay circuit. The idea is that I would connect the +ve output of the D3806 through the contacts of a Normall-Open 10A-rated relay.
When you switch on the ATX power supply (or any power supply) the relay contacts would remain open for approx. 1 second and then (after the D3806 nasty over-voltage spike had finished) it would close the relay contacts and connect the D3806 ouput to the output terminals.
The delay circuit worked great. I also designed it so that it would open the relay contacts on power-off/decay BEFORE the D3806 over-voltage spike ocurred on it's output too.
I had planned to use this device together with an old ATX power supply to make a nice variable, current-limited bench power supply.
So I decided to try to work around this issue and I designed a delay circuit. The idea is that I would connect the +ve output of the D3806 through the contacts of a Normall-Open 10A-rated relay.
When you switch on the ATX power supply (or any power supply) the relay contacts would remain open for approx. 1 second and then (after the D3806 nasty over-voltage spike had finished) it would close the relay contacts and connect the D3806 ouput to the output terminals.
The delay circuit worked great. I also designed it so that it would open the relay contacts on power-off/decay BEFORE the D3806 over-voltage spike ocurred on it's output too.