Neotronics Digiflam 850 Flammable Gas Sensor

Pictures from the inside of a flammable gas sensor from 1980’s England. Elton John says that “when you’re made in England you are built to last”. Well, this device is made with a Lead Acid battery potted to the case, so this one is built to last… Until the battery fails.

Note the conformal coating over the main board (though not all boards). The device uses 74 logic, and quite a few different daughter boards connected to the main PCB. The battery feeds 8V into the main PCB. It is charged by an external PSU via the barrel jack on the side. There is minor visible corrosion from the battery leaking. Two 5V regulators on the back of the case. Well built, except for the battery. Fundamentally flawed – it was not meant to live beyond the life of the Lead Battery.