spitfire
Walty McWaltface
That's why I'd do it with an old towel or similar on top, to stop the glass going anywhere.
An old towel isn't going to break glass dude.
That's why I'd do it with an old towel or similar on top, to stop the glass going anywhere.
Yes effectively a kind of OR gate.
Two diodes seems like an easy solution but I'm not sure if something weird happens when the thing is connected to both transformers at the same time?
Had considered relays but not sure exactly how that would work. I want the controller to get its power from one of the two transformers rather than from a third source.
Sometimes they are both on, sometimes it's just one or the other.Are both circuits ever on together or is it just one or the other?
Yep, two diodes will - in effect - create the OR gate you mention. You'll get a 0.6V drop across each diode, which probably won't be significant.Electrics.
I have a lighting controller thing that runs off 12v. The lighting it controls is powered via two transformers each of which outputs 12v.
I want the controller to be active when either of those transformers is switched on. I can't just connect it directly to the +12v of both transformers because then I'll connect the two lighting circuits together.
However, I think I can do this if I use two diodes. Is that right or is it not as simple as that? But if it is, I just find a diode that's rated for 12v & whatever current the controller draws?
Yes but doesn’t having multiple transformers increase voltage or current depending on whether they’re in series or parallel? Would a third diode solve that at the point where they join?Yep, two diodes will - in effect - create the OR gate you mention. You'll get a 0.6V drop across each diode, which probably won't be significant.
You will need to know the maximum current load, but, as an example, a 1N4001 diode is rated to 1A at 50V, but don't make the mistake of assuming that the lower voltage means you can use a higher current (ie, it's not a 50W device)
The somewhat rarer 6A05 (6A) or 10A05 (10A) will handle higher currents. All are available at sub-fiver prices.
Not really. On the assumption that what Teuchter is trying to do is to supply power to the controller from either (or both) of the transformers, the whole purpose of the diodes is to completely isolate the transformers from each other.Yes but doesn’t having multiple transformers increase voltage or current depending on whether they’re in series or parallel? Would a third diode solve that at the point where they join?
Ah, good. My assumptions appear to have reflected the reality.
Yes, agreed, but the controllers cost £50 and a diode seems to cost a pound or so.The easiest solution would be to have two separate controllers.
Actually I need to connect the controller V- to V- on both the PSUs, right? Not just one like I have drawn.Ah, good. My assumptions appear to have reflected the reality.
Yes, otherwise it would only work with one of the transformers. I can’t actually see what the controller is actually doing there other than being fed from two transformers.Actually I need to connect the controller V- to V- on both the PSUs, right? Not just one like I have drawn.
It's a DMX controller, so it sends control data via a completely separate data line. My diagram is simplified; the box that says "lights" is actually a DMX decoder connected to various lights.Yes, otherwise it would only work with one of the transformers. I can’t actually see what the controller is actually doing there other than being fed from two transformers.
Yes. Use 2 diodes connected to each transformer and joined together the feed the controller. You'll need diodes that will handle the current not the voltage.Electrics.
I have a lighting controller thing that runs off 12v. The lighting it controls is powered via two transformers each of which outputs 12v.
I want the controller to be active when either of those transformers is switched on. I can't just connect it directly to the +12v of both transformers because then I'll connect the two lighting circuits together.
However, I think I can do this if I use two diodes. Is that right or is it not as simple as that? But if it is, I just find a diode that's rated for 12v & whatever current the controller draws?
This. I hadn't thought about the issue of commoning the negative lines. Chances are, it'll be fine, but without knowing the full spec on the power supplies, we can't know if the outputs are completely free-floating with respect to earth, so doubling the diodes to isolate both sides makes sense.Yes. Use 2 diodes connected to each transformer and joined together the feed the controller. You'll need diodes that will handle the current not the voltage.
The transformers should be free floating wrt earth.This. I hadn't thought about the issue of commoning the negative lines. Chances are, it'll be fine, but without knowing the full spec on the power supplies, we can't know if the outputs are completely free-floating with respect to earth, so doubling the diodes to isolate both sides makes sense.
Basically it uses a big battery, the voltage is stepped up and fed in pulses down the fence. When the animals (or you) touch the fence you create a circuit between the fence and ground and get zapped at the next pulse.While yous are all here can anyone point me to some kind of beginners guide to electricity for proper idiots? Website/book/whatever.
Specifically electric fencing that's the main issue atm but it would be good to have a basic understanding of how this shit works generally.
This. I hadn't thought about the issue of commoning the negative lines. Chances are, it'll be fine, but without knowing the full spec on the power supplies, we can't know if the outputs are completely free-floating with respect to earth, so doubling the diodes to isolate both sides makes sense.
The transformers should be free floating wrt earth.
Yes the 2 negative lines will need joining together.
If you saw the whole of my wiring diagram, for the mains side of things, your eyebrows might be raised.I assumed the mains switches were double pole, but looking back at the schematic they’re not.