SparkFun Forums

[Ushtarador]

Hi forum

I am currently working on a project which involves generating ultrasonic pulses which are to be detected by another receiver.
As I am working with ultrasonic stuff for the first time, I just wanted to start by making a simple circuit and generate a continuous signal. I use a LM555 timer to generate a 40khz square wave, and now I would like to ask if I can just connect the ultrasonic transducer directly to the output+ground, or if I need some additional safety resistance/capacitance?

Thanks in advance

[leon_heller]

You can connect it directly.

[Ushtarador]

great, thanks

*waits for explosion cuz he does something wrong anyway*

[leon_heller]

They look a bit like a capacitor to the driving circuit.

[angelsix]

If it is the indoor (open can) type then yes fine to connect it right up. Provide it with around 30mA should be more than enough. Outdoor ones will need driving a lot higher voltage (at least all the ones I have found so far need too).

If you get stuck along the way I have full schematics and boards for both indoor and outdoor sensors you are free to use if you let me know.

Luke