John's Ramblings

When the switch opens the falling edge will cause a negative pulse on the 4013 input. The diode removes that negative pulse.

Input to 4013 without diode – one pulse (on/off) – zero volts is the centre line. The signal goes negative to minus 1.44 volts. Positive pulse comes from direct connection to +3 volts, negative [...]

Here is the final circuit I will use, the resistor and capacitor values give a time constant of about 0.5 sec – I’m sure many other values would work but I have these ones in my box.
I have added a pull down resistor on the reset line just to make sure it is low unless [...]

@MartinDix from CurrentCost kindly sent me a dev board so I could interface other feeds to the CurrentCost meter. After some experimentation this is the circuit I intend to use. I have not yet fully finalised values of components but it seems to work pretty well on the breadboard. Note my dev board is version [...]