Thanks for the extremely detailed reply.
Circuit 1 will only have a single LED lit at any given time so I'd require a 611 resistor (110/0.18) I believe. This would be fine to place just before the neutral return I'd imagine since it is a common path so should provide a load for each LED?
Thanks...
You're probably right that it is odd. However in the rail industry it would be something that would be extremely useful due to installation constantly being behind due to network constraints and other reasons.
Having a signal (traffic lights) in series with the lamp proving relay is the only...
This is the issue that I'm trying to overcome. 20mA isn't enough so I need a way to draw more. The LED is simply a visual indication to show that the circuit is working.
I'm not hiding anything nor trying to waste your time. The relay isn't in the schematic as all it would show is the feed...
Sorry, the load only needs to be around 180mA for circuit 1.
The second circuit requires a minimum of 3 LEDS lit for the current operated relay to pick. I believe the schematic should work fine, again its just working out the resistor values. This circuit requires 780mA and needs to lose...
What I'm wanting is essentially a dummy load.
In the real world the actual load would be a 110v Lamp. But to simulate this I'd like to have a small box with some LEDS in and I assume I'd have to have a resistor to limit the voltage going through the LED to provide a 200-400mA load.
If there...
basically I need to be able to operate a relay which is picked my around 200-400mA.
I'm trying to do this by passing a load through a resistor and an LED from a 110v AC supply. For example some
LEDS that I've seen have a 50mA operating current with a 2.5v drop.
I'm not sure how to work out...
The switches was meant to represent links;
Which are used to isolate the power to the signal head, show in the circuit posted in #43. Specifically these .
As you have stated in numerous previous posts Chris that I only need 1 dummy load and I have agreed with you I'm not sure why you are...
As I said it's an old circuit and ER1-4 isn't there since it was to prove your main filament hasn't failed, which you obviously don't have with LEDs.
Like I said that diagram was for Heavens to have a look at since it seemed like he was curious with how it's wired in the UK, which is similar to...
I did say in the post with the picture of the signal head circuitry that it is very old 20+ years. It was just to show Hevans the relays involved and how the circuit operates since he seemed interested.
These days there is no transformer and just 110V fed straight to the head. So hopefully no...
There is nothing in the signal head to indicate that the ECR is down other than having a black signal (no lights)
The ECR status is fed back to the signal box where the signaler will get an alert, he would also see on his panel that there is no lamp lit.
The only problem with this circuit is...
Haha, while I would love to make big bucks I don't there is quiet the demand unfortunately. It'll just be for myself and some others at work.
Here is a circuit head circuit, it's a very old one but everything is pretty much the same other than the Lamps themselves since we have turned to LED...
I again have to apologize for the fact that I explained this extremely bad.
As you mentioned you have one Lamp proving relay (Or current proving realy) for each signal head. This means one relay for your red, yellow and green in one, just to ensure that a lamp is at least lit.
It is rare to see...
Firstly you would never expect all 3 lights to be light on a traffic light right? Same thing applies here other than you have a double yellow (The four LEDs).
You can do this with just 3 LEDs since the second yellow isn't proved by the current operated relay, all you have to prove is the red...
You do technically only need one LED, in fact you don't really need any LEDs at all, just something to draw 300mA.
Just that having an LED for each lamp is aesthetically pleasing.