Digital Hour Meter Tachometer Maintenance Reminder Backlight Battery Replaceable for Small Gasoline Engine Lawnmower Snowblower Generator Lawn Tractor Motorbike Chainsaw（wire length 10ft）

My hyandia lawnmower,wrapped it around plug lead held for a minute and gave me a reading lots more on there but didn't need that section, always handy,well pleased as the take Lazer ones never work,take the battery cover off first

Bought this for my basic lawn tractor. Have set it up as per the instructions for a single cylinder 4 stroke engine. Have reduced the windings around the plug lead twice still showing revs over 5000! From an engine that B&S states only revs up to 2850!! I’m sure I will get there in the end!

Used this to monitor variable speed 12 volt 4 wire server fan in a DIY solder fume HEPA filter. The unit can be set to indicate when the filter needs changing which takes away the guesswork. The hack comprised of a 10K pull-up resistor on the fan output sense (tacho') output which is open collector, the current is thus limited to 1.2mA (max allowed =5mA). This is followed by a 5k current limiter and then a pull down to 0V 20k resistor. From the 5k/20k junction a 1nF capacitor removes dc component and supplies the tachometer input. The tachometer battery -ve is connecter to 0V. The true RMS pulse input to the tachometer was measured at 2.8V and was sufficient to provide a flicker free stable measurement of RPM.

I've had it since April keeping in mind mine hasn't really got wet but it's still working, I'm using on a motorcycle and it seems fairly accurate