what am i doing worng? relays got hot without load..

[mudale222]

hi guys,
got me 2 little relays from the store want to check them out.
one is 250v ac 10a. the second said 0.6a 125vdc, 0.6v dc, 2a 30v dc.
my battery is 74v. when connect the battery to the poles of the relays both of them got very hot in like 20 seconds even there is no load yet because other poles wasn't connected...

here is pics of them:

 

[Alan B]

That relay has a 24V coil. Don't feed it much over 24V.

The other ratings are for the contacts.

 

[mudale222]

alright thx.. i will look for higher coils relays..

 

[amberwolf]

What are the relays to be used for? We might be able to help you find better ones.

If it's for something on the ebike, there's not really any reason to use battery voltage to switch the relays with. The controllers usually have both 12v and 5v available, so you could use either 5v or 12v coil relays.

But you also have to have contact ratings on the relays that match what you are switching with them. So what are you turning on or off with the relays?

 

[mudale222]

what wire conducting 12v?
i'm using the relay to reverse electricity behavior for ebrakes.
i have the mt5e opener which mean that when u press the lever it's will cut the circuit otherwise it's a closed circuit.
In the controller to activate regen and motor cutoff u need to open circuit and not close one...
(black and white wire connector, neither to short it or send some voltage to black).
So what i'm doing with the relay is using it as normally open and when voltage cut it's will close and black and white will be short and come salvation to the world...
anyhow, i already thought about it yesterday and decide that i don't like the battery voltage to go to my handlebar so i'm going to use converter to 12v.. i'm anyway need to install it for other using....

 

[Alan B]

A 5v relay or a simple one-transistor circuit should handle the reversing you need.

 

[amberwolf]

what wire conducting 12v?

12v is usually available inside the controller (at very low current); it's usually what the 5v regulator is fed by. Sometimes this is also available on one of the wires to the outside, intended as a pullup for some types of braking circuits; you can check yours with a voltmeter.

I've used it for this purpose in an old generic 6FET; it was sufficient to trigger a tiny 12v relay salvaged from a UPS to switch brake lights. (I've also used 5v to power a similar 5v relay salvaged from a different UPS for teh same thing).

i have the mt5e opener which mean that when u press the lever it's will cut the circuit otherwise it's a closed circuit.
In the controller to activate regen and motor cutoff u need to open circuit and not close one...

Then your existing lever already does exactly what you want, because the lever opens a circuit, and you don't need anything else, if the controller activates regen/cutoff at circuit opening.

(Though this is the opposite of all the controllers I've run into, though, which require that you close the circuit, and would indeed require a relay or transistor or other inversion circuit.)

 

[mudale222]

no, sorry, i mean of course u need to close circuit to activate ebrake.
i just bought today a new same relay (because i cooked the last on e with my 80v battery (12v coil) )
installed the converter and the relay and it's work like a charm.
thx everybody