Buzzer vodoo
- Thread starter Chillum
- Start date
No, quite the contrary. The gate is a grounded element so it might help shield it a little, and more so if your gate is made of steel tubes and you run the cable inside the tubes.
That's a very interesting question... after all, one of the wire's ends goes to ground in your circuit... so maybe, you could ground that tip of the wire by attaching it to the gate, making electrical contact... maybe that could change its behavior, for better or for worse... you can always try and disconnect it if it misbehaves.
on the breadboard the switch isn't grounded, just 2 ends of the switch, it's still connected and it still hasn't misbehaved yet, so I think I should leave it as is...
edit: but grounding through the board or grounding otherwise should be the same
Ground the ground! connect your circuit's ground to the gate's metal... see what happens...
If I do that I change the breadboard design, and it' purring with just it's switch (pushbutton) that is connected to ground through the wires, and no otherwise ground, so I think I'll leave as is.
Sorry for being late to the party.
So if I can see it, your voodoo problem is caused by 25+10m of cable.
To mitigate the EMI problem you have to switch from a voltage signal to a current signal. That is, you have make the impedance of the switch, cable and resistor much lower and hence increase the current through the wire.
Change the pull-up resistor to the switch to about 220-470Ω.
At the trigger input of the circuit the capacitor is connected between the input pin and GND.
Make the electrolytic capacitor much larger, even as high as 10-100μF, with the negative lead to GND.
Wire a 0.1μF non-polarized ceramic capacitor across the electrolytic cap for high frequency filtering.
Please show your current circuit schematic so we can comment.
So if I can see it, your voodoo problem is caused by 25+10m of cable.
To mitigate the EMI problem you have to switch from a voltage signal to a current signal. That is, you have make the impedance of the switch, cable and resistor much lower and hence increase the current through the wire.
Change the pull-up resistor to the switch to about 220-470Ω.
At the trigger input of the circuit the capacitor is connected between the input pin and GND.
Make the electrolytic capacitor much larger, even as high as 10-100μF, with the negative lead to GND.
Wire a 0.1μF non-polarized ceramic capacitor across the electrolytic cap for high frequency filtering.
Please show your current circuit schematic so we can comment.
MrChips, you are VERY late ;-) buzzer8.2.pdf is the stable version of this whole buzzer bonanza; 3rd? day into testing on the breadboard (no EMI wires, short jumper cable) and still no spurious activity. The veroboard got modified to buzzer8.2.pdf specs and still had unstable activity; EMI was then suggested as the cause, but Reloadron suggested that I still get false triggers on the bench, so I said yeah I do, but that was before post 15 (buzzer8.2), so I set out to test the breadboard exactly as buzzer8.2.pdf and well, I mentioned it's the 3rd day without instability. So the solution to this party would be to move the box outside, with battery in a mostly waterproof lunchbox. I have a handyman coming in tomorrow (hopefully) and he's way better at wiring things so that its neat and tidy, my wires usually all over the place. So tomorrow we use <2m wire for the reed switch's connection to the board and the long cable for the piezo buzzer.
If that doesn't work, I'll come back and implement all your suggestions, but for now... it works! and if it works, I'm not touching anything!
If that doesn't work, I'll come back and implement all your suggestions, but for now... it works! and if it works, I'm not touching anything!
That's what I said but cmartinez said keep it exactly as post 15, I did, and you will have to provide a reason why it actually works 100% on the breadboard?
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I am not suggesting that my solution will work.
I have to go and read the entire thread and try to figure out what the circuit is suppose to do and what logic is required on the trigger input.
For whatever reasons, go ahead and install your current solution and live with the consequences.
I have to go and read the entire thread and try to figure out what the circuit is suppose to do and what logic is required on the trigger input.
For whatever reasons, go ahead and install your current solution and live with the consequences.
Mr Chips, I respect your opinion, I really do, but if it's not broken don't fix it... and what do you mean live with the consequences? Please, enlighten me, what consequences? Are you saying it will stop working because of...? I hope my tone is interpreted correctly, I'm actually honoured that you would join the quest for the voodoo ;-)
I need a buzzer 25m from the board that buzzes for only 6s and then stop even though the reed switch (normally closed) stays closed... I had spurious activity on my buzzing and that was the voodoo. and we (hopefully) detected the voodoo being EMI, that's the whole thread.
Mr Chips is right... he knows about electronics much better than me... I'm just a noobie-and-a-half in the analog electronics field, my area of expertise is digital and programming
All I'm saying is that it works, and if all these suggested changes are brought about, it might still work, but if it works, don't fix it. I think the cap is connected correctly because pin 2 needs to go low for trigger, not high?
Mr Chips suggestion was to change the circuit's operation mode from one that is voltage-actuated to current-actuated. Doing this change would not be too much work. But then again, this is not a life-and-death issue, so you still have the luxury of experimenting with what you have, and live with the consequences as @MrChips so ominously stated
... Anyway... I don't have the experience to answer that last important question of yours, about how long the battery will last... hope someone here answers it for us.
