Topband: Vacuum relay powering #2

[Harold Smith]

> Hi reflectees !
> I guess the relay issue is of common interest here.
> Even if a surface seems to be hard and rigid, the common contact surface 
> can be enhanced by extra pressure, with an accurate Ohm-meter You can 
> measure that. At a relay contact regularly there is dissipated heat, 
> pressure leads to a more common heat conducting body of metal and minimzes 
> thermal differences and surface bending by heating. Everybody who 
> contacted wires with sufficient current with bare fingers knows the effect 
> of pressure at metal to metal contacts. The relay manufacturer knows why 
> he says 26.5 Volts, he knows the magnetic force necessary to make a 
> contact pressure to yield the current allowance and specifications.
> At the cost of vacuum relays it may not be a good idea to save a penny per 
> year electricity for the coil and loose a 100 dollar+ relay.
> 73 de wolf  df2py



I must agree with Wolf.

If some one is using switched 12volts and want to use vacuum relays, It is 
very easy.

Pickup a Radio Shack 12 volt 1 amp power supply and put in series with the
common lead of your 12 volt relay supply.

Very simple.

Price W0RI