Laser tube hour meter CHEAP & EASY
Posted: Tue Apr 27, 2021
				
				I was looking around on eBay and AliExpress and spotted an hour meter for gas engines that do not require any hard wire electrical connections. It is a self contained module that has a long life battery and LCD display that is potted in epoxy. I got thinking this might work for monitoring the actual time the laser tube is working so I ordered one for less than $10 USD to check proof of concept. I installed this the other evening and ran a couple of jobs and so far I am happy with the results. This unit will only log time while the laser tube is firing and not during traverses of the head or machine operation time. 
For people like Gene that has two laser tubes in his machine a unit for each tube would be in order, a different color for each tube?
The connection part is really neat in that all you do is wrap the sense wire around the spark plug wire (in our case the high voltage lead of the laser tube) 5 times and secure it with a zip tie. DO NOT strip any insulation from either the high voltage lead or the sense wire, this is strictly an inductive connection. The other end of the sense wire pushes into a channel in the back of the module, again this is an inductive connection.
This module is not very granular in that it displays in tenths of an hour and updates every 6 minutes while in use. This is ideal to bench mark the tube and check degradation over long periods of time at various intervals.
I have included a few pictures below of the module and how to install it. If anyone else has already tried this or does try this I would like to know what kind of results you had.
			For people like Gene that has two laser tubes in his machine a unit for each tube would be in order, a different color for each tube?
The connection part is really neat in that all you do is wrap the sense wire around the spark plug wire (in our case the high voltage lead of the laser tube) 5 times and secure it with a zip tie. DO NOT strip any insulation from either the high voltage lead or the sense wire, this is strictly an inductive connection. The other end of the sense wire pushes into a channel in the back of the module, again this is an inductive connection.
This module is not very granular in that it displays in tenths of an hour and updates every 6 minutes while in use. This is ideal to bench mark the tube and check degradation over long periods of time at various intervals.
I have included a few pictures below of the module and how to install it. If anyone else has already tried this or does try this I would like to know what kind of results you had.