"Teledyne" couplers

[Anonymous]

From 1939 - 1941, Lionel had teledyne couplers which could open coil couplers using the whistle controller/current. These couplers are in the 622, 623, 2333, 1656, etc. With TMCC, this feature returns, but it would be nice to have it on the other postwar engines without having to install TMCC. Has CTT or other publication done an article on this? Robert Remley of the Golden State Division of TTOS did an article several years ago, which I can send in PDF Format; however, two of the parts are no longer carried by Radio Shack:

#1 R1 15K (ohm) Resistor Radio Shack part no. 271-036 What is wattage?

#6 X1 npn, n=50, 2n3053 Transistor Radio Shack part no. 276-2030 Could also be known as nte 128.

Any help would be appreciated.

Bob Gates, TTOS 6907

[lionelsoni]

You should be able to operate the couplers directly from the whistle relay. The only problem is that one of the relay contact springs is connected to the frame, and so is one end of the coupler coil. However, if you can remount the whistle relay so that it is insulated from the locomotive frame and instead connect the pickup to the relay frame, then the other relay contact can be connected to the coupler. The other end of the relay coil, that would normally be connected to the pickup, goes to the locomotive frame instead.

Insulating the relay should not be very difficult. It is mounted by one screw on the top. Put a piece of cardboard with a hole punched in it between the relay and the mounting surface. Use a plastic screw, or put a metal screw through an insulating shoulder washer. You may need to drill or ream out the hole that the metal screw passes through, to insure that the screw does not make contact with it.

I use a different scheme which does not involve the whistle. I add a relay which is operated from a small capacitor when a transistor detects voltage on the motor field winding. The capacitor is charged from the pickup voltage. The way it works is that you stop and turn the voltage up for a few seconds in neutral. Since the motor is disconnected in neutral, the unloaded capacitor is allowed to charge. Then when the locomotive next starts, the transistor turns on and operates the relay for a second or so, until the capacitor discharges. In normal operation, the load of the relay coil keeps the capacitor discharged, so the coupler does not operated unintended.

There's also a trick that you can use for tail switching that often makes it unnecessary to have direct control of the coupler. In a yard lead, install a switch to a short stub siding. Put a bumper at the end of the siding; and put an uncoupling track on the lead between the switch and the yard throat. Then you can uncouple a car or several by opening the locomotive's coupler with the uncoupling section. Then run the locomotive back over the switch, then onto the siding and into the bumper to close the coupler. Then return to the uncoupled car(s) and shove them into the yard's ladder track. This works of course with both types of couplers and even when you break the train elsewhere than at the locomotive. It allows you to spot the cars wherever you want in the yard and eliminates the need for uncoupling tracks on all the ladder tracks.

[Anonymous]

Thanks. I have done the "whistle relay" bit and it works fine. The only problem is (1) it requires cannibalizing a whistle tender and (2) since it is mechanical, it can be "stuck open" and damage the coil couplers (I have installed a warning light to guard against this). I am interested in your "electronic solution." I will try and e-mail you directly with an article and this thread.

I do think there may have been a CTT article on this and am still looking.

Best, Bob Gates, TTOS 6907

[lionelsoni]

Bob, I got the article you sent. As an aside to the coupler topic, it describes adding directional lighting to traditional Lionel locomotives. The author's method is to reconnect the lamp between the motor field and one of the brushes. This unfortunately requires ungrounding the lamp, which can be hard to do for those locomotives (like F3s) with the socket cast into the frame. He also puts in a 6-volt lamp, to compensate for the lower lamp voltage that results.

I had an article a while back in CTT describing my way of doing it, which requires only moving one wire. Instead of connecting the lamp between the frame and the pickup, as lionel did, you reconnect it between the frame and one of the motor brushes. The only disadvantage of this method is that the lamp does come on in reverse, but very dimly since the brightness of an incandescent lamp is very sensitive to voltage. It is hard to notice any light from outside the locomotive.

More later on couplers.

[lionelsoni]

This uncoupler circuit uses a relay powered from a capacitor. Turning up the track voltage for a few seconds while the locomotive is in neutral charges the capacitor. Then, the next time that the locomotive starts, the voltage on the field winding turns on a transistor, which operates the relay, which switches the track voltage to the coupler for a second or so. Operating the coupler as the locomotive starts is desirable, because a coupler will not always open when the locomotive is stationary and coupled to a heavy car or to another locomotive.

The negative terminal of the 1000 microfarad capacitor and the emitter of the 2N3904 transistor are both grounded to the locomotive frame. A 1N4148 diode in series with a 1 kilohm 1/2 watt resistor charges the capacitor from the track voltage. One end of the relay coil connects to the positive capacitor terminal. The other connects to the collector of the 2N3904 transistor, whose emitter connects to the frame. A 1N4148 diode across the relay coil acts as a snubber, with its cathode connected to the positive terminal of the capacitor. The ungrounded end of the motor field winding (the end connected to the e-unit) connects to the base of the transistor through a 1 kilohm 1/4 watt resistor. A diode with its cathode to the base and anode to the emitter protects the base-emitter junction from the negative half-cycles on the field winding.

I use this relay arrangement because the charging current adds to the current available from the capacitor for the relay coil and keeps the relay closed longer. However, it is possible for the relay not to release at all if the track voltage is fairly high, sometimes requiring me to slow down the locomotive after uncoupling to get the relay to release. I could increase the charging resistance and take longer to charge the capacitor, but I like the extra operation time of the relay that I get this way.

Another arrangement, that I formerly used and that you might prefer, completely shunts the charging current away from the relay. In this arrangement, the relay coil is in series with the capacitor. For example, there are in series, track voltage, charging diode, charging resistor, relay coil (with snubbing diode), capacitor, and frame. (The cathode of the snubbing diode is still to the positive capacitor terminal.) The collector of the transistor is connected to the point between the charging diode and the relay coil.

I use the Radio Shack 275-005 relay, which operates at 9 volts and has a 500-ohm coil.

[Anonymous]

Thanks. I will study your input. Best, Bob Gates