The Geiger counter module GGreg20_V3 has built-in protection against reverse polarity. This function is realized by means of a Schottky diode.
Additional documentation: GGreg20_V3 datasheet
The module can operate in two modes:
(1) with protection against reverse polarity;
(2) with an extended range of power supply voltage.
(1) Reverse Polarity Protection is in place
By default, the module supply voltage level can be in the range of 3.7 – 5.5V due to the presence of a Schottky diode in the circuit:
(2) Wider power supply voltage range
If you want to power the GGreg20_V3 from a 2.4 volt source, you need to short the Schottky diode shown in the photo with a wire or replace it with a 0 ohm resistor.
Please note, however, that this correction will disable the module’s reverse polarity protection.
This module is ready for use. The GGreg20_V3 modules are adjusted, configured and tested for compliance with the declared technical data before being shipped. Any adjustments or settings made by the customer may damage the module or introduce technical inconsistencies.
Please always weigh your strengths and competencies. Only qualified technicians should make such adjustments to the electronics.
Caution! The module contains high voltages, which can be potentially dangerous and may result in accidental electric shock if handled incorrectly.