2 minor
source | link

First, a comment: Your question would be clearer if you used the schematic tool available here on RPi SE.

schematic

simulate this circuit – Schematic created using CircuitLab

But the answer to your question is, "Yes, the second approach will work, and it is safe." In fact, it appears to be identical to the first approach from an electrical perspective. The essential points are these:

  • one side of each solenoid must be connected to one side of your supply voltage. It doesn't matter whether it's the 'plus' side or the 'minus' side, as long as you respect the polarity markings on all of your components.

  • the other side of each solenoid must be connected to one of the contact terminals on the relay.

  • the other contact terminal of the relay must be connected to the other side of your supply voltage; i.e. the side other than the one you connected to the solenoid coils.

The two schematics shown above are equivalent - either will work (again, as long as you respect the polarity markings on all of your components). I think the lower schematic may be what you've shown in your diagram.

If you're not used to thinking of electrical circuits, you can use a "plumbing analogy" to aid understanding. Imagine that the wires are pipes, the voltage supply is your water supply, and the relay contacts are faucets. If you close one of the relayrelays/faucetsopen one of the faucets, the water/electrical current will flow from your water/voltage supply into the sink/ground. That's a very hokey analogy; I don't like it, but some seem to benefit from the analogy - if you don't, please ignore it!

And calling your approaches serial or parallel is not quite correct, as they are neither serial nor parallel - they're simply 4 independent relay circuits!

If anything is unclear, please let us know, and we'll try to help.

First, a comment: Your question would be clearer if you used the schematic tool available here on RPi SE.

schematic

simulate this circuit – Schematic created using CircuitLab

But the answer to your question is, "Yes, the second approach will work, and it is safe." In fact, it appears to be identical to the first approach from an electrical perspective. The essential points are these:

  • one side of each solenoid must be connected to one side of your supply voltage. It doesn't matter whether it's the 'plus' side or the 'minus' side, as long as you respect the polarity markings on all of your components.

  • the other side of each solenoid must be connected to one of the contact terminals on the relay.

  • the other contact terminal of the relay must be connected to the other side of your supply voltage; i.e. the side other than the one you connected to the solenoid coils.

The two schematics shown above are equivalent - either will work (again, as long as you respect the polarity markings on all of your components). I think the lower schematic may be what you've shown in your diagram.

If you're not used to thinking of electrical circuits, you can use a "plumbing analogy" to aid understanding. Imagine that the wires are pipes, the voltage supply is your water supply, and the relay contacts are faucets. If you close one of the relay/faucets, the water/electrical current will flow from your water/voltage supply into the sink/ground. That's a very hokey analogy; I don't like it, but some seem to benefit from the analogy - if you don't, please ignore it!

And calling your approaches serial or parallel is not quite correct, as they are neither serial nor parallel - they're simply 4 independent relay circuits!

If anything is unclear, please let us know, and we'll try to help.

First, a comment: Your question would be clearer if you used the schematic tool available here on RPi SE.

schematic

simulate this circuit – Schematic created using CircuitLab

But the answer to your question is, "Yes, the second approach will work, and it is safe." In fact, it appears to be identical to the first approach from an electrical perspective. The essential points are these:

  • one side of each solenoid must be connected to one side of your supply voltage. It doesn't matter whether it's the 'plus' side or the 'minus' side, as long as you respect the polarity markings on all of your components.

  • the other side of each solenoid must be connected to one of the contact terminals on the relay.

  • the other contact terminal of the relay must be connected to the other side of your supply voltage; i.e. the side other than the one you connected to the solenoid coils.

The two schematics shown above are equivalent - either will work (again, as long as you respect the polarity markings on all of your components). I think the lower schematic may be what you've shown in your diagram.

If you're not used to thinking of electrical circuits, you can use a "plumbing analogy" to aid understanding. Imagine that the wires are pipes, the voltage supply is your water supply, and the relay contacts are faucets. If you close one of the relays/open one of the faucets, the water/electrical current will flow from your water/voltage supply into the sink/ground. That's a very hokey analogy; I don't like it, but some seem to benefit from the analogy - if you don't, please ignore it!

And calling your approaches serial or parallel is not quite correct, as they are neither serial nor parallel - they're simply 4 independent relay circuits!

If anything is unclear, please let us know, and we'll try to help.

1
source | link

First, a comment: Your question would be clearer if you used the schematic tool available here on RPi SE.

schematic

simulate this circuit – Schematic created using CircuitLab

But the answer to your question is, "Yes, the second approach will work, and it is safe." In fact, it appears to be identical to the first approach from an electrical perspective. The essential points are these:

  • one side of each solenoid must be connected to one side of your supply voltage. It doesn't matter whether it's the 'plus' side or the 'minus' side, as long as you respect the polarity markings on all of your components.

  • the other side of each solenoid must be connected to one of the contact terminals on the relay.

  • the other contact terminal of the relay must be connected to the other side of your supply voltage; i.e. the side other than the one you connected to the solenoid coils.

The two schematics shown above are equivalent - either will work (again, as long as you respect the polarity markings on all of your components). I think the lower schematic may be what you've shown in your diagram.

If you're not used to thinking of electrical circuits, you can use a "plumbing analogy" to aid understanding. Imagine that the wires are pipes, the voltage supply is your water supply, and the relay contacts are faucets. If you close one of the relay/faucets, the water/electrical current will flow from your water/voltage supply into the sink/ground. That's a very hokey analogy; I don't like it, but some seem to benefit from the analogy - if you don't, please ignore it!

And calling your approaches serial or parallel is not quite correct, as they are neither serial nor parallel - they're simply 4 independent relay circuits!

If anything is unclear, please let us know, and we'll try to help.