I'm working on a simple project with off-the-shelf modules, that will add volumteric control to a home espresso machine (what this essentially does is use a hall-effect flow meter on the tank-to-pump pipe coupled with an electronic timer relay (in counter mode) that counts the pulses from the flow meter, stopping the coffee machine at a preset count). Simple...
However, whilst this all starts very nicely when the 'brew' switch is hit - and the machine stops automatically at the preset point - the electronic timer relay then needs to be manually reset (by hitting a "reset" button on it). I'd like to avoid this if possible, but I can't think of an easy way to do it.
What needs to happen is:
1. There's a 240V circuit that drives the pump, that's switched on when the brew switch is on - I'd like to use this as the initial trigger. There's then a pin on the timer controller that, when connected to +12V (another pin) momentarily will reset the counter (as if 'pushing' and releasing a momentary push "reset" switch)
2. So, when this 240V circuit is switched on, I'd like a separate 12V circuit to go on briefly and the off again - and remain off (until the 240V is switch off, reseting the circuit).
With my very basic knowledge, I'm assuming that there's going to be a 240V relay that, when energized, will switch the 12V circuit - but I only want that 12V circuit to remain on very briefly (perhaps 0.1s) and then switch off again.
Can anyone help me with a relatively simple way to do this, and avoid having to manually press this "reset" button all the time?
Many thanks for any help or advice that anyone can offer.
However, whilst this all starts very nicely when the 'brew' switch is hit - and the machine stops automatically at the preset point - the electronic timer relay then needs to be manually reset (by hitting a "reset" button on it). I'd like to avoid this if possible, but I can't think of an easy way to do it.
What needs to happen is:
1. There's a 240V circuit that drives the pump, that's switched on when the brew switch is on - I'd like to use this as the initial trigger. There's then a pin on the timer controller that, when connected to +12V (another pin) momentarily will reset the counter (as if 'pushing' and releasing a momentary push "reset" switch)
2. So, when this 240V circuit is switched on, I'd like a separate 12V circuit to go on briefly and the off again - and remain off (until the 240V is switch off, reseting the circuit).
With my very basic knowledge, I'm assuming that there's going to be a 240V relay that, when energized, will switch the 12V circuit - but I only want that 12V circuit to remain on very briefly (perhaps 0.1s) and then switch off again.
Can anyone help me with a relatively simple way to do this, and avoid having to manually press this "reset" button all the time?
Many thanks for any help or advice that anyone can offer.
