HV 400V Geiger Driver Two Channels for Muon Cosmic Ray Coincidence Detector

Miniature fixed 400V high voltage output module with 2 channels for 2 Geiger Tubes. 
Has GM pulses buffer circuit with digitized shape pulse output on every channel. That allows to connect it directly to a micro-controller for building DIY Digital Dosimeter or DIY Muon Cosmic Ray Coincidence Detector. The pulses can be read on SIG1 and on SIG2 output.
The board has A0 analog output that allows to measure high voltage constantly by a micro-controller ADC.
Can be integrated into battery operated portable equipment or used for laboratory setup.
 
Technical specifications:
Fixed High Voltage Output 400V
Number of Channels: 2
Compatible with many popular 400V GM Tubes
~ 10.0uS TTL digitized pulse output of GM pulses, 3.3 logic level
Ability to drive long probe signal cable
Input supply voltage 5.0V-5.5V
Output current 40uA at 400V
Quiescent battery current ~ 1mA 
Includes 10M load resistor on the PCB for every channel
Compatible with PIC / AVR / MSP / Arduino
Physical dimensions: 43mm x 24mm
Shipping Weight: 150gr
UPC Number: 634154871171
SKU: RH-K-GK-HV-4
 
UNIQUE High Voltage Geiger Tube Driver for two tubes and with two channels signal buffer. Can be used for building DIY Digital Dosimeter with 2 tubes or for DIY Coincidence Detector. 
Because of the high energy, muons can trigger two Geiger tubes with a sheet of lead between them almost simultaneously whereas normal background radiation and other particles will only trigger the two detectors randomly. Background gamma radiation is not energetic enough to pass through both tubes (and the lead) and trigger them both. Thus, when you get a coincident detection, it is very certain to be a muon.
If you want to monitor high voltage on tubes with microcontroller ADC you can use A0 module output. It has about 2000mV DC for 400V.
 
Board Pinout:
S1 - tube#1 pulse
S2 - tube#2 pulse
A0 - analog output for ADC
GND - ground
5V - voltage input 5V DC
Anode and Cathode connected as shown on the diagram