jocanon
Member
So this is just in the idea stage right now, but I wanted to create this post anyway so that I can get some input in formulating my idea. The problem I need to solve is I have two 12v power supplies connected in series (DC isolated on upper one) in order to create one 24v power supply. Everything works fine unless/until one of the PSUs goes out but the other keeps going. Then you have a situation where the fan is not running on the one that is off but the one that is working is still pulling current through the one that is turned off with no fan to cool it. What happens is it heats up and eventually starts to smoke if the one that is working is not turned off. I want to build something that will prevent this from happening.
My idea so far is a circuit that is in-line with the mains AC power cord so that it will just turn off power once it detects voltage has dropped below say, 18v. I already have an on/off switch in-line with the AC power cord routed through a Hammond ABS plastic enclosure, so it would be easy to integrate other logic circuitry at that enclosure. I am not an EE, but I think I could do that with a comparator circuit and a relay pretty simply, but I will need some help building the actual circuit. Or, if there is an even more simple, safer, or just better idea to solve the problem that I have not thought of, please chime in and let me know.
Safety is the keep issue here. I need some out of the box thinking to solve this problem. I want it to be a plug and play thing that I can give to anyone that has such a 24v supply that they can just use this for their AC power cord & on/off switch and run the DC output through it as well in order to detect when voltage has dropped. I am picturing it all fitting nicely in an ABS enclosure that Velcros to the top of the series PSUs with AC power coming in one side, on/off switch mounted on top, and DC output coming out the front...maybe for extra bells and whistles, if I want to, even putting a little volt meter and/or current read out on there as well (but that's for another thread...). We are running high currents at 24v, about 50 amps. Is my idea a good one? Is it possible? Thanks!
My idea so far is a circuit that is in-line with the mains AC power cord so that it will just turn off power once it detects voltage has dropped below say, 18v. I already have an on/off switch in-line with the AC power cord routed through a Hammond ABS plastic enclosure, so it would be easy to integrate other logic circuitry at that enclosure. I am not an EE, but I think I could do that with a comparator circuit and a relay pretty simply, but I will need some help building the actual circuit. Or, if there is an even more simple, safer, or just better idea to solve the problem that I have not thought of, please chime in and let me know.
Safety is the keep issue here. I need some out of the box thinking to solve this problem. I want it to be a plug and play thing that I can give to anyone that has such a 24v supply that they can just use this for their AC power cord & on/off switch and run the DC output through it as well in order to detect when voltage has dropped. I am picturing it all fitting nicely in an ABS enclosure that Velcros to the top of the series PSUs with AC power coming in one side, on/off switch mounted on top, and DC output coming out the front...maybe for extra bells and whistles, if I want to, even putting a little volt meter and/or current read out on there as well (but that's for another thread...). We are running high currents at 24v, about 50 amps. Is my idea a good one? Is it possible? Thanks!