Laser LS8000-3 manual Appendix D Supply Voltage Requirements, Dual Conductor Supply, @2.0A

LaserSpeed 8000-3 Instruction Handbook

Appendix D: Supply Voltage Requirements

Appendix D: Supply Voltage Requirements

The LS8000-3 gauge requires a supply voltage of 20 to 28 Volts DC at the gauge. Because the gauge can draw over 2A of current, Voltage drop across long cable distances may be a problem. The LS8000-3 normally only demands this high current just after power on, or when the ambient temperature is near the upper limit. This is when the gauge is cooling the internal optical components with the most power. If you are using cables not purchased from Beta LaserMike, please review this section before designing the cable interface to the gauge.

The LS8000-3 gauge has two power input pins (pins 24 and 25) and two power ground pins (pins 12 and 13). Cabling wires to all four pins (Quad Conductor Supply) will allow you to use smaller wire diameters while avoiding voltage drop problems. Cabling wires to only two pins (one power, one ground—called Dual Conductor Supply) requires larger wire diameters. This manual section will discuss how to size your supply wires correctly to eliminate voltage drop problems.

Dual Conductor Supply

If you are using two conductors (one supply wire, one return wire), the following table will help you determine your total voltage drop across the cable.

Wire Size	Wire Size	Voltage Drop per Foot	Voltage Drop per Meter
(AWG)	(mm2)	(@2.0A)	(@2.0A)
26	0.129	0.16	0.54
24	0.205	0.10	0.34
22	0.326	0.065	0.21
20	0.518	0.041	0.13
18	0.823	0.026	0.083
16	1.31	0.016	0.053
14	2.08	0.010	0.033
12	3.31	0.0064	0.021

Voltage Drop using Single Supply/Single Return

Example: Your power supply is 200 feet (61 meters) away from the LS8000-3. You are using a single 20 AWG wire to supply power to pin 24, and a single 20 AWG wire as a ground (connected to pin 12). Your voltage drop in the cable will be:

Voltage Drop = #Feet * Voltage Drop/Foot = 200 * 0.041 = 8.2 volts

Part No. 93463 / Drawing No. 0921-01561 Page 202 of 221 Revision A (Sep 2007)