Series Power Supply Safety Circuit

tvtech

My little things worked just fine. No issues.

(a) Was an emergency. We had to keep a valve open, or we could have been down for a month.

(b) It worked out fine too. later we got rid of the stick/TIG welder and replaced it with a smaller MIG welder. I've use all three, but we didn't have any one proficient enough to do the repair. The original joints were done with an automatic "orbital welder" and then the tubing bent in place.

ronv said:

Here is a take off on 4pyros idea. Gets back to one switch.
Couple of things.
1-The red light will be on when it is plugged in. Maybe not such a bad thing.
2- You will have to hold the off switch in the off position until the power supplies drain or it will turn back on. This might be a problem. Might want to check that time with no load again.

Click to expand...

Ron;
What red light are you talking about?
I get the off circuit but the on switch would have to be a momentary to work wired like that other wise it would keep bypassing the relays the hole time its on.

I just drew in a neon bulb for the red one.
Yes, momentary on / momentary off.
I suppose we could use a toggle switch. You can get them in on, nothing and momentary. That would help the off time problem, but give a no mans place in the middle. With a rocker switch it is kind of natural for it to pop back to the middle.

ON-none-(ON) has no middle position.
ON-OFF-(ON) would.

Jo, if you want or need the 24 V relay let me know. I know I have some somewhere around here.

Ron

Here is a better one using logic instead of comparators.

awesome...now that 4-15 tax deadline is over, I may actually be able to test this out. (although I still have a major deadline non-4-15 related, but it has to be done today! ) I should have saturday off...i still have the other dummy load to build too.

Since your the designated marketing guy we should disclose the warts:
On a fault the red LED will not stay on, but will go off as the supply discharges.
When you turn it off the red light will also come on until the supply discharges. We could make it go off as long as the switch is in the off position, but it would probably come back on after you let go of the rocker since the supply takes a few seconds to discharge.

So I discovered the new power supplies I am working with do not have any short circuit shut off protection. How difficult/possible would it be to incorporate that into the design of this idea as well? Here is the thread about the short circuit problem:

https://www.electro-tech-online.com/threads/power-supply-pop-why.140660/

Maybe the resistor used to power them up could be tripped if the leads touch?

nevermind on short circuit protection...it does have it already built in after all.

jocanon said:

nevermind on short circuit protection...it does have it already built in after all.

Click to expand...

Well ya it would be crazy to make a power supply that big on current for a server without protection.

Hey.

I have a dedicated PSU protection circuit already for sale;

https://www.rcgroups.com/forums/showthread.php?t=2070862

This unit works on the DPS-600PB's (plug in on this PSU type.
I have a dedicated one for the DPS-1200 units as well, with the right resistor value to turn them on.
I also have a negative switch type that is useable on most server PSU types.

Basically this protection circuit senses the output volts and switches off both PSU's should the supply voltage drop outside of my programmable range.

I have another unit coming soon with a few more features, control of up to 3 PSU's, volts and amps display, temperaure controlled outputs, bluetooth capability as well for I'm hoping connection to hand held devices for sending information to. I can't remember it all off the top of my head.
Here are some very basic videos of the prototype in development now.



Ian Contessa