Continue to Site

Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

looking for a pulse relay

Status
Not open for further replies.

igeorge

Member level 5
Joined
Oct 31, 2010
Messages
85
Helped
1
Reputation
2
Reaction score
2
Trophy points
1,288
Activity points
1,956
I have a thermostat project which run from 2AA batteries
The microprocessor has a minimum consumption current
In fact the whole project run in just 1-2 miliamps.
The big issue is the output of thermostat.
Most thermostats, to conserve power , and change the battery maybe once a year , use latching relays.
2 coils take too pins from micro
1 coil is complicated to drive
I heard about pulse relays. One pulse = ON; take the power out and still ON, like a latching relay. Next pulse, on the same line, turn it OFF.
I found circuits to drive 1 coil latching relays, but most of them use capacitors, which of course will drain my battery
I need a suggestion of a manufacturer for this PULSE relays.
Contacts 2 A, coil 5-12 VDC
 

If you are switching about 1A AC you can use a current transformer that will give you 50mA to hold on a normal relay and to charge your battery.
 

Thanks Vbase, but maybe i did not express myself correctly
I need to have the power on the PIC pin just on the transition moment, then the pin will drop at 0 volts and no consumption.
The relay, must maintain the last position.
At next pulse, it must toggle the opposite way. I do not know what will be the voltage on the contacts of the relay. Every HVAC manufacturer has its own way of internal activating the heat or cool.
 

Status
Not open for further replies.

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top