Ben, Neil, all.
I have a pic of completed board, should be easy enough to replicate..... unless someone has bought rights to Dave’s designs of course.
Please e-mail me for a copy if you are interested.
Colin de G8LBS.
Mail for Windows 10
Hi Ben, I have a number of these in use......
Someone was supposed to take over production (DX Shop ?) when Dave died but I think it never happened, I may be wrong though.
I got one spare for future use. Attached is the configuration PDF in case it goes walkies into a data black hole one day.
Been looking for a PCB layout but no luck yet.
Colin de G8LBS
Mail for Windows 10
If they don't have tellback contacts, there is a bit of a problem in knowing the current state of the relay following loss of power for instance. I've just bought some HP latching jobs with 3.5 mm connectors and no tellbacks, so I have the same issue as
you. This one I have on the bench at the moment is rated at 15 V and pulls about 170 mA. The others I have all come with separate tellbacks or internal contact so the current drops to zero once the relay has flipped.
The way I'm dealing with these is to use a PIC as a sequencer and just send a half-second pulse to a low-side FET switch.
Not exactly low-tech. How about a small double pole relay with two resistors and two electrolytics? Electrolytics sized to give a 200ms pulse on the relay and a resistor with 10 times the value of the coil resistance to recharge the cap? You'd end up with
a small current through the active coil all the time on rx and tx, but only 10 mA.
On 25/03/2021 11:10, militaryoperator via groups.io wrote:
There was a thread a while back about lathing relays.
The ones I had required a voltage, they latched then pulled no current.
One's I have just got need volts to latch then pull about 100mA if volts left on. As they don't need volts all the time, what's the best way, circuit etc, to
pulse them, common goes to ground and a 12v pulse on 1 or 2 needed to latch etc.
Just trying to avoid over-straining my few remaining brain cells, and not re-invent the wheel again.