Table of Contents
GCA120 Heavy load relay
The prototype
Description
The GCA50 or CAN-GC2 are only able to switch 25mA by 5 Volt on each output.
This is fine to switch a relay like Omron GV5-1 but then there is only 1 Amp maximum allowance.
Even that 1 Amp is too much, if the relay has to switch the full load many times.
That is my experience.
To make it possible to switch up to 10 Amp, a bigger relay is needed, and also some way of controlling that relay from LocoNet.
One option is to switch a relay like Omron G2R by use of GCA77.
But if you need to setup a GCA77, just for the relay only, then this unit provides all in one.
One side is connected to an output of GCA50, and to a power adapter 12-16V dc or transformer with max 18V ac.
The other side has a connector which provides a Normal open and normal close contact. One or both can be used.
I constructed this because most railroad will have (at least I have) a transformer for feeding illumination and also for the power to GCA76, GCA77 or GCA136.
In order to be able to use that transformer for powering this relay, an on-board opto-coupler separates the supply from LocoNet GCA50.
Anything up to 10Amp can be switched now.
The MGV120 is developed to switch a max of 42 Volt.
The relay will be able to handle 230V, but CE regulations demand an open space of 5mm between tracks on the pc-board and connections.
Both connector J2 and the tracks to the relay do not comply with that.
Also, an correct isolation is not taken care for.
So 42 V is the maximum allowance.
Depending of the used supply, please consider that the relay must be adapted to that. See bill of materials.
Specification
- Opto isolated input for 5-12Vdc (like from GCA50 or CAN-GC2).
- 42V - 10Amp power switching.
- supply 12 Vdc or 16 Vac (look in bill of materials for differences).
Bill off materials
Qty | Ref. | description supply 12 dc | description supply 16-18V ac | |
---|---|---|---|---|
2 | R1,R3 | 2K2 | 2K2 | |
1 | R2 | 10K | 10K | |
1 | R4 | 330E | 330E | |
1 | C1 | ELCO 220 uF 25V | ELCO 220 uF 35V | |
1 | Lg1 | LED 3mm green | LED 3mm green | |
1 | D1 | DIODE 1N4002 | DIODE 1N4002 | |
1 | D2 | DIODE 1N4148 | DIODE 1N4148 | |
1 | T1 | BC517 | BC517 | |
1 | K1 | OMRON G2R 12V alt. FIN 40.31.9 12V | OMRON G2R 24V alt. FIN 40.31.9 24V | DARISUS alt. Reichelt |
1 | K1 | OMRON G2R 12V | OMRON G2R 24V | |
1 | J1 | AKL012/04 | AKL012/04 | |
1 | J2 | AKL012/03 | AKL012/03 |
The design
The schematics |
The pc-board + parts placement |
N.B. Self made pc-boards are not supported! |
---|
All connections are signed at pcb drawing.