Re: Door Latch Actuators

[Frank Pittelli <frank-at-rctankcombat.com>]

Joe Sommer wrote:
> 
> I thought that they were solenoids with
> spring return.  If they are motors, you will
> need reversing capability.

They are small motors with a pinion gear that pulls or pushes a rail 
depending on the polarity applied to the motor.  No limit circuitry at 
all ... when the actuator is fully extended, it stops mechanically and 
the motor is stalled.  No reversing capability is needed either, because 
when the voltage is turned off, the trigger spring is strong enough to 
return the trigger and actuator back to the armed position.

> 
> Do you have a favorite model of 5A relay that you prefer?

Those little blue ones work fine.

> 
> 500 ms seems a bit long.  That only provides fire rate of 2 bps.
> 

Sure, assuming that the person holds the button down for that long.  I 
was thinking that the 500ms would be the maximum time that the circuit 
would allow the actuator to be energized before the button is released 
and pressed again.  If, however, the button is released before the time 
limit is reached, then the circuit would simply respond accordingly. 
The time limit serves only to prevent the motor from being energized for 
too long (in case the joystick doesn't return to center, for example), 
not for regulating the firing rate.

        Frank P.