In another posting I asked for ideas on how to add red and green LEDs to the switch tracks of an N Gauge model electric train. See below for my earlier post.
It seems like the way to go would be with DPDT Dual Coil Latching Relays.
I would like to obtain a few (< 10) DPDT Dual Coil Latching Relays that will work with both AC and DC impulses to the coils.
Digikey, current catalog page 1229, has24VDC 3,200 7.5 2 2 16.8/16.8/48 255-1068-ND
a DPDT dual coil latching relay.
A couple of questions:
- The 16.8/16.8/48 is in the Pickup/Dropout/Max. Voltage column of the catalog page. Why isn't the middle entry a "-" as it is for some of the other dual coil latching relays? Does this mean that the coil must have a continuously applied voltage of at least 16.8 volts? This doesn't seem to make it a *latching* relay.
- All of the relays on page 1229 state that the coil voltage is DC. Could some of these also be used with AC, if the AC is just a momentary pulse, say for a relay with a 16.8/?/48 entry in the Pickup/Dropout/Max. Voltage column?
- Does anyone know where I might obtain an AC/DC DPDT relay that holds the setting with no voltage other than a pulse to the coil?
A self-latching relay seems like the simplest solution, except for the questions that I have (above).
My previous post:*********************** I have an N-gauge train with some remote-controlled switch tracks, "snap-switch" type.
This is an older style train, not the DCC type.
I would like to add red and green LEDs to the switch tracks. The switch tracks are operated from the "accessories" terminals of a small power supply which are nominally 17 V AC, (I measured it open-circuit at 17.7 V AC).
The switch tracks are operated by pressing momentarily on a momentary SPDT switch.
I'd like a simple way to hook up the LEDs either at the remote location or at the SPDT switch. Since power to the switch track is applied only momentarily, I suppose that some sort of latching mechanism is needed.
The 17 V AC is part of the complication, it seems.
For reference, the switch tracks are Atlas #'s 2580 and 2581; the power supply is Model Rectifier Corp. Railine 370N.
The switch tracks are apparently solenoid powered.
The power for the tracks only is 15 V DC. I wouldn't want to power the LEDs from that terminal pair because it turns off when the train is stopped, and includes the speed control.
Anybody here ever do this stuff with this type of remote turnout?
My guesses are some sort of relay or solid state relay, but I have no idea what the specific part number or circuit would be.*****************