VRS Signal conditioner and pulse divider
A VRS Signal Conditioner takes the unconditioned output from a Variable Reluctance Sensor (VRS), eg: an ABS wheel speed pickup, which is a noisy sine wave and outputs this as a clean square wave signal (similar to the output from a Hall Effect type sensor), suitable for connection to a DL1, DL2 or DASH2.
It can also divide the pulse frequency by a number between 2 and up to 32. Typically ABS sensors read a wheel with many slots, which gives a high frequency signal. By dividing the number of pulses the signal is better suited for use with a DL1, DL2 or DASH2.
The VRS signal conditioner can be used to condition the VRS signal, divide the pulses coming from a wheel speed sensor or both.
When ordering a VRS signal conditioner we therefore need to know whether the signal needs to be conditioned or not and what number (if any) to divide the pulses by. This information is based on the intended speed range and the number of teeth on the wheel speed sensor.
Technical specification
The VRS conditioner / divider takes in either a square wave signal of between -20V and +20V or a signal from a variable reluctance sensor (VRS sensor) and produces a square wave output at 0-5V suitable for use as a wheel speed or engine speed input to a data logger or dashboard. As well as conditioning the signal, the circuit can divide the input pulse by up to 32 to give a lower frequency output.
Connections
|
| wire
| Description
|
Input
| Black
| Signal ground
|
Black/white
| Input signal
|
Power/Output
| Red
| +12v
|
Blue
| GND
|
Green
| Direct Pulse Output
|
Yellow
| Divided pulse output
|
Power supply
|
Supply voltage
| 7-16v
|
INPUT
|
Mode
| Input voltage range
|
VRS mode
| 0V to 57V
|
Non-VRS mode
| -20V to +20V
|
OUTPUT
|
Mode
| Output
| Voltage
| Duty Cycle
|
Direct mode
| Divided by 2
| 0-5V square wave, 5V TTL levels
| 50%
|
Divided output
(Divide range: 4-32)
| 0-5V square wave, 5V TTL levels
| 50%
|
VRS mode
| Divided by 2
| 0-5V square wave, 5V TTL levels
| 50%
|
Divided output
(Divide range: 4-32)
| 0-5V square wave, 5V TTL levels
| 50%
|
The VRS is connected up as shown in the diagram below: