trainman6555

Hello all, This is my first question. I have spent 2 days trying to fathom out the answer and have finally come to you all! I have this diagram, found in several places on the web. Now this looks good. Anything set wrongly prevents actuation by diverting the power via a diode away from your point or signal switch so it wont work. Great. Big issue is, as it is, the locking diode creates a dead short across the relay supply. Not so good. It is suggested a lamp or LED is inserted in the circuit to prevent this. Now I'm not so dumb, so I built it on my bench. Obviously the LED idea needs a series resistor. This drained the power. The lamp I used just took all the power out of the circuit too. The relays that were not locked just dropped out. I tried series, parallel, but to no avail. Bottom line folks, can anyone complete the drawing above without a short? Or loss of current to other relays not shorted by diodes? I have done my truth table and am ready to build! Thanks

Hi, a little bump here! Just a note, the skew bridge 100 yards from my house in Derby, on Stenson Road, if you want to google it, has 20 panels per side, used to cross 4 tracks and has NO additional support. It has large stone butresses. It carries 32 ton trucks on their way to the local supermarket and has no weight limit! My new Wills bridges won't be that long and I figure will not need support either.