34
Race Technology Ltd. VAT reg. 715 9671 09
After 12, King Street, Eastwood, Nottingham, NG16 3DA, UK
Tel: +44 (0) 1773 537620 Fax: +44 (0) 1773 537621
Email: [email protected]
In this case we need to use a "pull up" resistor to convert the changing resistance to a
changing voltage:
1 wire sensors are the same, but in this case the 2nd wire on the sensor is ground and
made via the sensor body earthing to the engine casting etc.
Once the sensor is connected to the DL1 CLUB with the pull up resistor then it can be
calibrated in the normal way.
8.7.1
Choosing a value for the pull up resistor
Please note that it is the installer responsibility to choose the correct value of “pull up”
resistor when using 1 or 2 wire sensors with Race Technology products. For a particular
sensor type there is no “correct” value of resistor however it must be selected to be
“somewhere near” to ensure:
•
There is a reasonable voltage swing, ideally this wants to be a “few volts” rather than a
few “milli volts”. A small signal can get easily lost in “noise”.
You cannot take too much current from the 5v reference output, depending on the product
typically this cannot be more than a total of 100mA.
Summary of Contents for DL1 MK3
Page 1: ......
