I am posting this in the hope it may help with the tachometer installation of a fellow Dynon user. I am an RV4 driver who recently updated with the Skyview system. Thought I could save someone some grief from the research that I did during my installation. My bird was previously equpped with a LASAR ignition system and a Vision Micro V1000 engine monitor.
LASAR Ignition - The attachment is for the LASAR tachometer specifications.
- The LASAR tachometer signal outputs whether on L,R, Both or whether the LASAR ignition is off when doing a mag check.
- Short story is you need to add some resistance to the signal in front of the EMS connection. I tried a few different resister values before settling on 15K ohm resister. This stabilized the signal. From the Dynon manual you will not that the voltage needs to fall below 0.8 volts DC to trip the frequency counter in the Dynon systrem. Hence the need for the resister to drop the voltage.
VM1000 - Tachometer sensor. This is a small sensor that screws into the side of the left Slick Magneto. Diificult to find anyone out there that has a spec sheet for the sensor. I will tell you that I couldn't get this sensor to interface with the Dynon system but may have surrendered a bit early as I switched my efforts to the LASAR system before conducting the tests I will share with you
- Here is what I did. I had a spare slick mag in the shop. Connected a new tachometer sensor to the slick mag and the sensor to the old VM microprocessor box with a 12 V power supply to the box.
- The microprocessor box outputs 5V DC to the sensor. This is also conformed from an old troubleshooting guidline I had received years a go from VM.
- I have the seen the sensor referred to as a hall effect transucer on other threads but not sure that this is an accurate reflection. The sensor appears to simply turn the voltage output on and off as the mageto magnet passes by the sensor.
- I measured 5 volts DC on the white sensor lead and when turning the magneto it would drop to zero volts. This occurred twice per revolution of the magneto. Not speed dependant so I an suggesting it resembles a switching action more than an emf induced current flow.
- The red wire on the sensor should be connectded to 5 volts DC and the Black is the ground connection.
Your milleage may vary but these are my observations.
As another point of interest. I installed the GRT amp donut on the alternator output to measure amps. I found I had to reverse the arrow on the donut to measure positive amps. i.e. the arrow had to point to the alternator. Backwards from the instructions. Your milleage may vary.
Tom Brown
RV4Brown@ptd.net
LASAR Ignition - The attachment is for the LASAR tachometer specifications.
- The LASAR tachometer signal outputs whether on L,R, Both or whether the LASAR ignition is off when doing a mag check.
- Short story is you need to add some resistance to the signal in front of the EMS connection. I tried a few different resister values before settling on 15K ohm resister. This stabilized the signal. From the Dynon manual you will not that the voltage needs to fall below 0.8 volts DC to trip the frequency counter in the Dynon systrem. Hence the need for the resister to drop the voltage.
VM1000 - Tachometer sensor. This is a small sensor that screws into the side of the left Slick Magneto. Diificult to find anyone out there that has a spec sheet for the sensor. I will tell you that I couldn't get this sensor to interface with the Dynon system but may have surrendered a bit early as I switched my efforts to the LASAR system before conducting the tests I will share with you
- Here is what I did. I had a spare slick mag in the shop. Connected a new tachometer sensor to the slick mag and the sensor to the old VM microprocessor box with a 12 V power supply to the box.
- The microprocessor box outputs 5V DC to the sensor. This is also conformed from an old troubleshooting guidline I had received years a go from VM.
- I have the seen the sensor referred to as a hall effect transucer on other threads but not sure that this is an accurate reflection. The sensor appears to simply turn the voltage output on and off as the mageto magnet passes by the sensor.
- I measured 5 volts DC on the white sensor lead and when turning the magneto it would drop to zero volts. This occurred twice per revolution of the magneto. Not speed dependant so I an suggesting it resembles a switching action more than an emf induced current flow.
- The red wire on the sensor should be connectded to 5 volts DC and the Black is the ground connection.
Your milleage may vary but these are my observations.
As another point of interest. I installed the GRT amp donut on the alternator output to measure amps. I found I had to reverse the arrow on the donut to measure positive amps. i.e. the arrow had to point to the alternator. Backwards from the instructions. Your milleage may vary.
Tom Brown
RV4Brown@ptd.net