Why is my relay bank not working?!?!

[boyd]

Hi. Pretty good exercise huh? I am no where near as familiar with electronics as you guys. But very close inspection gave me a better idea on how the board worked.

I would love to know where they are available for US$99c delivered to NZ.

But the irony is, that the board will still not do the job I need it too. So I will be cutting it in half and just using the seperate inputs to each relay in-depandant of the others. And will work fine for purpose
.
I have learnt lots. Thanks so much.

My next job is fixing a low voltage power supply section of a programmable module I have managed to procure but has a blown section which powers the 24VDC sensors.

Kind Regards
Boyd

 

[73's de Edd]

Clarification . . .as per . . . .

Well that's what is making the relays run?

Over at the relay proper, it is receiving 12 VDC into its coil with the other terminal of the relay coil going to the
collector of the driver transistor. The sensor portion of the secondary of the optical isolator is wired in series with a select value resistor to provide base drive to the transistor to activate the relay.
The separate and totally isolated primary of the optical isolator, with its sensor illuminating LED, only needs a series limiting resistor to be able to take 5 volts and light its LED to activate the secondary of the optical isolator.
This then leaves the option of letting the associated resistor get connected to ground , where the incoming INPUT 1-2-3 or 4 line (s) will have to supply the +5vdc @ 20 ma to activate its LED.

OR if that select resistor is connected to a 5VDC source from the boards supply.( It could be reduced down from that 12VDC), then a grounding of the INPUT 1-2-3 or 4 lines would light up the primary ' s LED to activate the optical isolators secondary's sensor.

The mentioned good closeup photos would help in confirmation.



No . .NO . . .NO NO NO . . . .you NEVER get free delivery .
Shipments have to be placed in holding warehouse until the weekly or bi weekly collection is made at the arrival time of airplane.
Then a mass loading for all shipments . . .final . arrival at individual countries holding warehouses . . . . . and then a final delivery by most honnable rickshaw driver.

73s de Edd

.