Tachometer with Progressive Shift Light

This is a compact tachometer, counter, and frequency meter. It displays the RPM from a pulse-sending unit.  It has the ability to calculate and convert the pulse rate to RPM or any other unit. The gauge has an internal relay that turns on at the programmed speed. In addition, it comes with a small  LED board that can be mounted on a dashboard. The LED board has tri-color high-intensity LEDs. A user can program the LED color so that it can display three different colors at a specific RPM range. This feature will help the driver to shift the gear without looking at the instrument panel.

This gauge accepts input signals in the -30V to +30V range. It can work with optical couplers, proximity sensors (such as Auber's SM8-310), Hall sensors, or encoders. 

Features:

• Three measuring modes: tachometer (RPM), frequency meter (Hz), and counter.
• Input power 12 - 30V DC. 
• Supplies 12V and 5V DC to an external light or buzzer.
• Digital LED display with a range from 0 to 9999.
• Adjustable LED brightness.
• Support a progressive shift light with 4 assigned ranges.
• One relay output that can be activated by high/low limit alarms.  
• Built-in timer to record time since the meter is powered on.
• Two multipliers that enable the user to do a simple conversion on the raw signal.
• (Optional) 12VDC LED board can be used as a progressive shift light.    

The ASL-41 tachometer and the optional LED board. 

Application Example:
Use the shift light (included in the product package) to indicate a different range of the measured input signal. The ASL-41 is used as a counter (P-Sn = 3). Settings: A1 = 10, A2 = 20, and A3 = 30. The color of the shift light changes as the counted number increases and passes the threshold set by A1, A2, and A3.

When the input signal is less than A1 (10)	When the input signal is between  A1 (10) and A2 (20)	When the input signal is between A2 (20) and A3 (30)	When the input signal is greater than A3 (30)

Specifications:

Input signal range	Signal low: -30 V ~ +0.6 V; signal high: +4 V ~ +30 V.
Input sensor type	Optical coupler, proximity sensor, hall sensor, encoder
Power supply requirement	DC 12 ~ 30 V
Power consumption	Less than 2 W
Relay contact rating	3 A
Relay life	100,000 times
Sampling	1 second; maximum measurable frequency: 50 KHz
Display range	0 ~ 9999
Measurement range	1 - 9999; 60 - 9999 RPM; 1 - 6000 Hz
Accuracy	±0.3%  of full input range; or ±1 unit
Gauge display size	0.26'' digital LED display
Working condition	0-60 °C, 0-85%RH
Panel cutout	45 x 22 mm
Dimensions	48 x 24 x 65 mm
LED shift light power input	12 VDC

[PDF] Instruction manual of ASL-41.