I've not used a capacitor in any of my experiments/projects yet and wondered if introducing one here would help conserve battery life.
I plan to install a basic 'alert' system in my shed which will tell me if the door is opened through the night. I have purchased a magnetic door switch from flee-bay and hacked this into the switch of a wireless door-bell transmitter.
When the door is opened, the reed switch closes the circuit and the battery sends current through the RF transmitter and I'm abruptly woken by Green Sleeves chimes
The problem, If I have the door open for any length of time, I imagine the battery will drain pretty quickly since the circuit will be closed constantly.
I was wondering, if I swap out the reed switch for one that closes the circuit while the shed door is closed, the battery could perhaps charge a capacitor? On opening the door, the switch would open and the capacitor would discharge via the RF transmitter. This would happen only once per door opening. Would this work? or would the capacitor cause constant drain?
My challenges:
Where do I position the capacitor to ensure it discharges via the RF transmitter and not directly into the battery.
How do I work out the type and size of capacitor I need? The battery that powers the doorbell is 12v(23A). Does the picture of the circuit give any clues?
I've attached an image to help clarify...