What is the voltage regulation for solar panel operation?

Technical Note No. 031

Voltage Regulation for solar panel operation for 2B instrumentation

Date: 27 June 2012

Author: Craig Williford

Summary: The pump and pump circuitry can be damaged by voltages higher 
than 14 Volts on 2B ozone monitors models 205 and 202. When using solar 
panels in remote locations, voltages typically exceed this voltage level during 
peak sunlight hours and can break down the pumps quickly and damage the 
pump control circuitry leading to board failure. This occurs with improper voltage 
regulation from the solar panel charging unit. To avoid this, we suggest using an 
voltage regulator inserted internally between the input power and the printed 
circuit board (PCB) or externally between the external power source and the 
instrument. The voltage regulator will ensure that the voltage supplied to the 
instrument is 12 Volts.

Parts needed: 
1 x DC-DC converter (V-Infinity PN: VCD30-D12-S12-T)
Black and Red wiring

Procedure for Internal Mount
1. Remove top cover of Model 202 or Model 205.
2. Cut the red and black wires at the midpoint and strip both cut sides. 
3. Locate a place on the instrument base plate to mount the DC-DC 
converter.
4. Extend the cut power wire ends from the chassis side by splicing new 
wiring so wires will reach “-Vin” and “+Vin” where “-Vin” is black and “+Vin” 
is red.
5. Ensure that exposed wire is covered with electrical tape or heat shrink.
6. Cut and strip new black and red power wire leads to extend from “-Vout” 
(black) and “+Vout” (red) to the other cut ends from step 2. 
7. Solder or splice the wires together and cover exposed wires.
8. Cut and splice another black wire to exten from “Case” on the voltage 
converter to the chassis using the existing chassis ground screw on the 
power in for the connection.