Hi all, My names Richy and im looking to build a project torch (everyone must start somewhere). I am a novice but keen to listen and learn.
The project involves a 5 x 1.2 watt Cree LED lighthead with integrated driver (spec available if needed), an 8.4v battery pack and a piezo momentary switch. I am wanting/hoping that the product listed on the Pololu website as “Pololu Pushbutton Power Switch SV” will allow me to switch the battery power to the lighthead.
Any advice is most greatly appreciated as its the only part of the project im stuck on.
That sounds like a great project to start with - LEDs are a lot of fun, and you might even get something useful out of it. Our pushbutton power switch is in some ways ideal for a flashlight, and the output of the switch will probably have no trouble driving your lighthead.
However, our pushbutton power switch does not work well with piezo switches. I think the problem is that a piezo switch makes a gradual connection over a few milliseconds, rather than turning on instantaneously like a traditional switch. You might be able to switch the circuit on and off by tapping it sharply with your fingernail, but normal finger presses will probably work disappointingly poorly. You could try it, but most likely you will have to either go with a normal button or find a different on/off circuit.
Ah, that’s a shame I’m glad I asked now. It’s a divelight so needs to be piezo ideally and this looked like a very neat solution. Is it unreasonable to assume nothing could be retrofitted to your circuit to make it more sensitive, I know there are switches with ‘transmit’ power signal for longer duration.
I look forward to hearing from you, I haven’t abandoned hope just .
I actually started looking into the possibility of using piezo switches a year or two ago after seeing some posts by divers on another forum, but I never got very far. It is likely that some of the parameters of our circuit could be tweaked to make it work much better with piezos, and if we ever make another version of the board, that will definitely be a consideration. However, right now I do not have any good suggestions for you. Probably everyone else who makes a piezo button power switch uses a monitoring circuit of some sort that is always on and consuming a tiny bit of power.
