Voltage controlled relay

Thread Starter

rtm038

Joined Oct 18, 2009
2
I'm looking for a simple circuit that will turn a standard Bosch automotive relay "On" at 10 volts and "Off" at 10 volts. This relay will be used to control (2) other relays in my truck, which has a 12+vdc electrical system. The approximate specs on the Bosch relay are: Pull-in voltage= 8 volts; Drop-out voltage= 1 to 5 volts; Coil resistance= 0.160 amps (75 ohms). Any help would be appreciated.

Ryan
 

mkbutan

Joined Sep 30, 2008
299
Bosch automotive relay "On" at 10 volts and "Off" at 10 volts.
Bosch relay are: Pull-in voltage= 8 volts;
i did nit understand the concept of 10V & 08V
 

bertus

Joined Apr 5, 2008
22,278
Hello,

You could make a voltage comparator that switches round 10 volts.
This comparator could switch the relays.

Greetings,
Bertus
 

SgtWookie

Joined Jul 17, 2007
22,230
I'm looking for a simple circuit that will turn a standard Bosch automotive relay "On" at 10 volts and "Off" at 10 volts.
Hello Ryan,
I'm afraid that I'm not quite understanding your stated requirement.
Your threshold for both "on" and "off" is 10v.
Did you mean that for any voltage over 10v, you want the relay 'on', and any voltage under 10v you want the relay 'off'?

Or did you mean that the first time a level of 10v is detected the relay turns 'on', and the next time it goes 'off'?

Or did you mean something else entirely?

I am also curious about the 10v threshold; why that particular voltage?

If you are attempting to disengage a system before the battery is fully discharged, please be aware that a lead-acid battery with a core temperature of 25°C/77°F is considered fully discharged when the battery voltage is 10.4v; and allowing an automotive battery to become so discharged is very hard on it.

This relay will be used to control (2) other relays in my truck, which has a 12+vdc electrical system.
OK, it would be most helpful if you would describe as best you can exactly what you are attempting to do with this single relay controlling the two other relays.

The approximate specs on the Bosch relay are:
Pull-in voltage= 8 volts
Drop-out voltage= 1 to 5 volts
Coil resistance= 0.160 amps (75 ohms).
Any help would be appreciated.
It's very helpful to have the relay specifications; glad you included them.

Please describe the project in more detail, as best you can, starting with an overall concept statement; something like "I want to make sure my fog lamps are turned off before my battery goes dead". The more complete your information is, the more quickly we can help you successfully complete your project.
 
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