agriculture aplication.

[bravootome]

I am in. I forgot my password for few months, but i am in.
I think i had asked for this once but i cant find the topic, so
I need a cannon to scarry the rabbits, it will be a gas cannon, it has to make noise every 10 min but i must be able to set the time. What i do not know to make is that controller that :
1. opens the gas valve for few sec and close it ( i must have a way to set it also)
2. wait for a while so the gas can mix inside
3. make the spark ( i got the solution)
4. reapeat the process over and over again
5. in the morning it should stop by itself ( i got a solution for this with some sun pannels ......)

the controller will work with 12 V car battery

i am looking for a way to make it by using parts already made, i got few ideas but i can not write them in english....

I know those controllers can be found on e-bay, but there is no e-bay here.

[mrfoo]

Open / close the gas valve : You need a solenoid valve, relay, and a controller to action the relay.
Spark : automotive coil, spark plug with opened gap, relay, 12v supply, something to trigger the relay again.

I'd suggest using something like a teensy microcontroller, a couple of transistors to drive the relays, and a bit of home brewed software.

[bravootome]

Open / close the gas valve : You need a solenoid valve, relay, and a controller to action the relay.
Spark : automotive coil, spark plug with opened gap, relay, 12v supply, something to trigger the relay again.

I'd suggest using something like a teensy microcontroller, a couple of transistors to drive the relays, and a bit of home brewed software.

Thanks for the answer but i know i need a solenoid valve, a 12 v supply, a relay doesnt stay open 1-2 seconds...... it is about the times ,,,,,
I am looking for a link with a "how to", some schematics , something.....

[mark.f]

https://www.arduino.cc/en/Tutorial/HomePage

You should be able to pick some of what you need out of there.

[mrfoo]

a relay doesnt stay open 1-2 seconds

A relay will stay "open" as long as you're energising the coil.

You'll be lucky to find a "how to" for this.

There'a few ways to go about it.

The "easiest" way is to use a microcontroller to generate the signals you want. Everything is programatically controllable, but you need to be able to program.

The other way is to use something like a 555 to generate your long timebase, and use that to trigger astables for the "fill/wait/spark" cycle. No programming required, but harder to tweak.

In any case, your outputs will be at 3v3 or 5v and minimal amperage, you need to boost them and isolate the higher voltages from your controller electronics. Either using relays or darlington pairs and opto-isolators.

FWIW, I wouldn't rely on timing to get your mix correct, you want an injector that mixes at the same time.