12V. RELAY QUESTION.

[drivesafe]

Hi Chimpboy, contrary to your post, I have never stated that wiring them the way I have them in the diagrams is better, my argument is about someone making statements that indicate there is a standard when there is not and that the way I have them in the diagram is incorrect when again there is no standard.

Plus deliberately misleading statements like ALL relays have suppression built in also does nothing to advance the credibility of the person making these fictions statements

There is no reason why people can’t adopt use the pin 85 as neg and 86 as the positive and at no time have I stated otherwise.

I’m sorry to have dragging this out but I have had a gut full of people who will post any lie for no other reason than to win some form of pissing competition.

To mada1234 and others, I apologies but I’m sorry I no longer have time or patience to put up with the lies that get passed off as being fact and I’ll call a spade a spade when it’s needed.

As posted in my last reply, there is enough crap and bogus info being spread by many of the advertisers in this field without having supposedly helpful fellow forum members deliberately posting misleading info for no other reason than to win a pissing contest.

Cheers.

[Dooley]

Hi Dooley, rapid80 has covered that and my hat off to him for trying to protect so called sensitive equipment.

BUT, the use of any form of EMF suppression actually has nothing to do with protecting so called sensitive equipment because there is no sensitive equipment used in the automotive industry.

Every single bit of electronic equipment in your vehicle is already protected by its own built in spike suppression.

To back this point, there are many thousands of people, and I’m sure this includes quite a few on this forum, who use nothing more than a good old fashion unsuppressed solenoid and NONE of them ever has a problem with electronics being damaged.

Dooley this is not aimed at you but there is so much crap out there, usually put out by unscrupulous Isolator sellers making claims that their isolator will protect your vehicle because they have added spike protection.

This is nothing more than a truck load of horse droppings.

If you were to fit one of their device and they hadn’t fitted their wonder spike protection, absolutely nothing would happen to the electronics in your vehicle, BUT the isolator’s own electronics would be fried after just a few operations.

If the penny hasn’t dropped, these isolators need the spike protection to protect the isolators own electronics and they offer no protection to your vehicle and the sellers implication that their spike protection will protect your vehicle’s electronic is nothing more than an advertising con job.

While we are on the subject advertising con jobs, can someone explain how a device the size of a 10 cent piece inside these isolators, can give a vehicle surge protection, when the biggest surge protection device in your vehicle, your cranking battery can’t. And more to the point why do you need surge protection in a 12v DC system?

I think you misunderstand me... I'm not talking protecting some other circuit or some sort of voodoo magic sales bull.

I mean say if for example a relay was driven by an onboard computer/microcontroller etc.... think CANBUS, OBD etc. then I think it would be inadvisable to replace a relay with a diode across the coil for one without. Bad practice at best.

The simple fact being that an IC or transistor/FET etc. may be driving that relay and the back emf when the field in the coil collapses would not be doing them any good...

To answer your last question. The spike is from the collapse of the magnetic field in the inductor. Haven't done the exact maths but internet hearsay says at 12v it could get up to 200v...

[bansheebuzz]

85 neg 86 pos that is the standard, we didn't learn that in trade school for nothing, and i have not seen a normal relay sold these days without supression(this does not include solenoids)

[-Scott-]

Oh good, another internet forum pissing contest.

I think we're getting unnecessarily caught up in semantics, using "correct" and "advisable" interchangeably.

There is no "correct" was to wire a non-diode suppressed automotive relay - either way works.

The trade school idea of wiring them all the same isn't a bad idea - it won't hurt anything to wire all relays that way. But to say it's the "correct" way to wire all relays is incorrect.

ICs and surge suppression. 20 years ago, all digital IC I/O had surge suppression diodes built into the chip, at the pad on the silicon wafer. I don't know what happens these days, but I would be disappointed if such suppression diodes are no longer standard practice.

We also need to understand that not all "suppression" relays use the same circuit. As drivesafe pointed out, some use a "flywheel diode", which makes the relay polarised, and the pin connections are important. Those suppression relays which use a resistor-capacitor circuit are not polarity sensitive, and will work either way.