Switch replacement - Python programmer out there?

[Spittybug]

Don't forget the diodes if you're hooking relays up to your RPi. When you stop providing current to a relay, it causes quite a large voltage to appear. This voltage can quickly fry your expensive raspberry pi.

I'm an embedded engineer by trade. I've wanted to do an entirely modern replacement delorean electrical system for a long time. I wish I had the time for it...imagine being able to remove the miles of wiring and replacing them with a modern data bus......it would be so wonderful.

--buddy

I believe the relay board has on-board optoisolators for that protection. http://www.ebay.com/itm/8-Channel-5V...item53fc734328

[nullset]

I believe the relay board has on-board optoisolators for that protection. http://www.ebay.com/itm/8-Channel-5V...item53fc734328

That has optoisolators and the diodes.

There's no need for relays for any of this though. It's all reasonably low currents and could easily be handled with MOSFETs in a much smaller package.

[LordFly]

There's no need for relays for any of this though. It's all reasonably low currents and could easily be handled with MOSFETs in a much smaller package.

Window motors, door popping solenoids and headlights are low current?

[nullset]

Window motors, door popping solenoids and headlights are low current?

Reasonably so, especially given the exceedingly low duty cycle.

Headlights would probably be the only thing I'd consider medium to high current.

A friend of mine is working on this: www.motobrain.com

[Tomcio]

Window motors, door popping solenoids and headlights are low current?

No problem with driving those with MOSFETs. I'm driving OEM cooling fans like this and the transistors don't even get hot.
BTW, those solenoids that change gears in an automatic transmission are driven with MOSFETS.

[LordFly]

Sorry, I'm from the world of small electronics. Anything over 1 amp is high current to me

[Spittybug]

That has optoisolators and the diodes.

There's no need for relays for any of this though. It's all reasonably low currents and could easily be handled with MOSFETs in a much smaller package.

Relay board is cheap. $10 for 8 relay and other sizes available. I already have one and it's not very big. I'll take your word that it is overkill, but it's also plug and play, at least from a hardware point of view.


With the interest this thread is generating and with several of our members having considerable talents in this arena, perhaps there is a group collaboration opportunity? I don't see this as an end product that could really be sell-able because of the degree of customization and butchery for an individual to put it in their car. But if the project were "open source" per se, then all could give it a try if they wanted? I'll volunteer to PM it, despite my lack of programming skills. As I've said, I do indeed intend to educate myself on this stuff! Let me know if you are game.....

[Bitsyncmaster]

Those relays are rated for 10 amps max. So they could drive one door actuators maybe the solenoid since they only run for one second. One headlight but probably not two since headlights are on a long time. One window motor as long as you don't stall it to long.

[Exolis]

Those relays are rated for 10 amps max. So they could drive one door actuators maybe the solenoid since they only run for one second. One headlight but probably not two since headlights are on a long time. One window motor as long as you don't stall it to long.

Agreed, Head lamps will probably need a higher rated relay. Do consider the in rush current by a headlamp, I've seen in rush current of up to around 40A, granted it's for a short period of time, but doing that on a low rated Relay will shorten the life considerably. So I would recommend finding bigger relays.

As for programming, Python is on my to do list, probably after I get comfortable with LabView. I do love the idea though. I've been slowly doing some stuff to redo the entire harness with the addition of an IPDM.

[LordFly]

Use those relays to drive the standard 30/40A relays that are available everywhere. Those will run your headlights all day long.
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