I'm puzzled by the drive arrangement for the relay. You have pins 15 and 16 of U1 shorted together? Doesn't the coil current polarity need to be switched?

 

Are you sure that 1kΩ in series with the relay coil provides sufficient current to reliably latch the coil under all conditions?
That only puts about 4.6V across the coil.

 

Wot, no back-emf protection diodes on the relay drive?

 

Wot, no back-emf protection diodes on the relay drive?

Good catch.
The COM pin on the UL2003 needs to be connected to the +12V supply.

Is wot textspeak for what?

 

I'm puzzled by the drive arrangement for the relay. You have pins 15 and 16 of U1 shorted together? Doesn't the coil current polarity need to be switched?

Good catch.

 

Good catch.
The COM pin on the UL2003 needs to be connected to the +12V supply.

Is wot textspeak for what?

Very good catch. Thx

 

Are you sure that 1kΩ in series with the relay coil provides sufficient current to reliably latch the coil under all conditions?
That only puts about 4.6V across the coil.

Correct. The schematic is incorrect. I'm using 100 ohms and didn't update the default values. Another good catch.

 

Thanks for the corrections. Schematic updated.

 

You still don't show catch diodes for the relay coil back-emf.
[Edit: Ah, I see they're incorporated in the ULN2003 and are effective when COM is connected correctly.]

Is wot textspeak for what?

The 'wot' is indeed 'what', but not textspeak. It was used by the Mr Chad character. Here's the historical background.

 

You still don't show catch diodes for the relay coil back-emf.

The 'wot' is indeed 'what', but not textspeak. It was used by the Mr Chad character. Here's the historical background.

Well, I can see the my knowledge of British History is indeed lacking.

 

Thanks again for everyone's help. This is what you contributed to making possible:

http://www.w5fcx.net/2017/03/26/wireless-j-box-design-v0-2/

Cheers!
Rick/W5FCX