Hall sensor output

[MG David]

I am building and MS1 v2.2.

The MS1 Extra Ignition Hardware Manual provides 2 different set of mods to the board for hall sensors depending on whether the tooth coming in front of the sensor takes the voltage up or down.

I have bought a Honeywell Microswitch Geartooth Sensor 1GT101DC. Link below. It is described as current sinking. Does that mean the volts are up with no tooth and when tooth comes in front the the volts go down?

Secondly, in the diagram in MS1 Extra Ignition Hardware Manual it shows the 5v supply, presumably from pin 26, routed via a 10R. R will be resistor but does the 10 mean 10 ohm?


http://sensing.honeywell.com/index.php?ci_id=50300

[t3chnician]

Current sinking is different than the rising/falling edge. Current sinking is an indicator of where the current comes from and indicates whether the Hall Sensor is made with a PNP junction or an NPN junction so you can basically disregard that. At the bottom of the Honeywell technical datasheet you posted, you will see that the Honeywell sensor output goes high when it sees a gap, so that would make it a 'rising edge' sensor. When it sees the tooth the output goes low. Also, I see the diagram with the supply voltage connected to a '10R' to the sensor and I see the confusion there. First, they did not use a 'resistor' symbol, and there is no mention of a 10R resistor, so I don't think you need one. In fact, I don't think you want to put a resistor there. So I would say that the 10R is some sort of reference number, connector number or something, but it doesn't mean put a 10 ohm resistor there.

[MG David]

Thank you very much. I had almost given up on a reply.