coil whine on electrified lockset and other questions


Active Member
(all measurements I am talking about are at the lock/solenoid) If you have access to an oscilloscope you could look at the wave form of the 12v... if not, if you have a multimeter with a frequency counter function that could be interesting. If you have just a regular meter, check the DC voltage.
It should work fine installed at either end of the cable. It sounds like the PWM is at an audible frequency- if you found one that operated at a higher frequency, you should not be able to hear it. Maybe the unit that DEL mentioned above.. I can't find anything specific on the 7200 as to exactly what it is, so somewhat of a guessing game.


Active Member
The HES SMART PAK 3 has showed up and I installed it yesterday. It looks like I have a winner. No coil whine whatsoever, and nice, cool operation. I am having difficulty in measuring the actual power use, but pulled power from an M1 PD9HC and would not trip the PTC, so it is somewhere under 400mA.

​@DEL - many thanks for the suggestion

amperage is measured in series, voltage in parallel.
Ohm's law comes out since the voltage is decreased to a hold voltage but amperage is a function of the equation. Can't give the inverse/ratio due to rum at the moment.