Special Relays for low voltage circuit

I am building a device that runs on regular batteries and I need to use relays in it. Are there special relays for these sorts of low voltages and currents?

One of the relays needs to close a circuit once the pd in the main circuit is above 2 or 3 volts (main circuit will reach 15 volts on occasion).

I need the other relay to close a switch once the pd gets above 12-14 volts (I have a capaciter charging and I need it a circuit to close when it reaches close to maximum charge). Is there a special relay that I can get that will close a switch at the specified pd of 12-14 volts.

any help much appreciated.

Rupert

Reply to
Rupert
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This really sounds like a job for a solid state device. I could cludge you up something with zeners, transistors and op amps but I bet someone would jump in with an off the shelf solution so I will defer to the guys with the fat catalogs on their desk.

Reply to
Gfretwell

In article , snipped-for-privacy@hotmail.com says... | I am building a device that runs on regular batteries and I need to | use relays in it. Are there special relays for these sorts of low | voltages and currents? | | One of the relays needs to close a circuit once the pd in the main | circuit is above 2 or 3 volts (main circuit will reach 15 volts on | occasion). | | I need the other relay to close a switch once the pd gets above 12-14 | volts (I have a capaciter charging and I need it a circuit to close | when it reaches close to maximum charge). Is there a special relay | that I can get that will close a switch at the specified pd of 12-14 | volts. |

Operating at set voltages has never been the design function of a relay and the power consumption of relay coils does not mix very well with battery use.

Consider using an op-amp comparator circuit to detect the voltage (compare against a reference), then perhaps an analogue switch IC to act as the relay. Use of the latter item will depend on the voltage and current you intend to switch.

Reply to
Harry Bloomfield

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