[MAMS] relay driver

[Dr. Gerald N. Johnson]

There are at least a couple two coil latching relay schemes. One is just 
two coils tha you only need to apply a pulse to for a short period and 
the relay mechanically or magnetically latches. I don't see a 
restriction in the catalog that requires power be removed from the coil 
right away except that the current of some latching versions at 12 volts 
is 230 ma and the same relay not latching (fail safe) is 195 ma, so 
there's more heat in the relay with continuous coil power. Then, of 
course, it takes applying power to the other coil to change the relay 
position. Coils often have one wire in common and are polarity sensitive 
so that prevents some simple drive circuits based on conventional relay 
drive.

Some Dow-Key also have a self cutoff circuit, so keep the power 
consumption low by taking care of interrupting the coil current on their 
own to make the drive circuit simpler.

I have portions of a recent Dow-Key relay catalog on my other computer 
but need a model number to know what you have and how to drive it.

73, Jerry, K0CQ

On 9/7/2012 12:47 PM, Danny Pease wrote:
> I picked up a two coil 12 volt latching DowKey SMA relay and am looking for
> simple suggestions for using it or I would be glad to trade it for a non
> latching SMA relay, 12 or 24 volt.
>
> Danny NG9R
>
>