https://www.patreon.com/AppliedScience ---- Donate here! I built a tiny radio into a ballpoint pen that allows the user to hear audio by casually biting the pen.
This looks like a fun project. I think I can build this, but looking up the components on digikey returns a bunch of results (with different capacities). Would you be able to provide a parts list for this build? Particularly the Piezo transducer and the Impedance pieces. Thinking i can connect these to a headset and have music...in my head. Thanks!
Thanks. The Digikey part number for the impedance matching transformer is in the comments section on youtube. I don't have a part number or source for the transducer, since it was just pulled from my shelf of junk. It's probably something like this: http://www.steminc.com/PZT/en/piezo-ceramic-disc-10x2mm-r-215-khz-wire-leads-smd10t2r111wl
Hi there! Could you explain a bit about how the tranformer performs impedance matching? I understand the basics of complex impedances and bode plots, but don't really understand how you can "match" the impediance of a device or what that might do. For now I've just been playing mine through speaker amps at a really high volume, but that doesn't work too well. My transformer (Digikey MT4148-ND, in case another needs it and the youtube comment disapears) is in the mail. Thanks so much for all you do!! You've had a great impact on my life and inspired a lot of projects
Jake, thanks for the kind words. Here's an analogy to help understand impedance matching: Suppose you have a 120V tungsten light bulb, and a "D cell" battery. You want to illuminate the light bulb. If you connect the battery directly to the bulb, very little current will flow, and the light bulb will not illuminate. The reason is that the bulb's resistance has been designed to work with a 120V supply, but we are only giving it 1.5V from the battery. The devices are mismatched because they are operating at different voltage levels. The result is that very little power is transferred because of this mismatch. If we had a black box that could convert the 1.5V from the battery into 120V with no power loss, the bulb would illuminate because the voltage level is now matched. The black box could be a transformer for AC circuits because it can match the voltage from one device to the design voltage of another device without losing much power itself. Having a perfectly matched set of devices means that maximum power will be transferred.
I got inspired to test this out myself. Can I hook the transformer up to 32 Ohm impedance audio output backwards? Datasheet shows that pri source impedance is 1.6 kOhm and sec load 3.2 Ohm.
This is a very interesting project, and it might be worth giving a tech article presentation at my tech school. Could you please make a video that explains how to create it?
This looks like a fun project. I think I can build this, but looking up the components on digikey returns a bunch of results (with different capacities). Would you be able to provide a parts list for this build? Particularly the Piezo transducer and the Impedance pieces. Thinking i can connect these to a headset and have music...in my head. Thanks!
ReplyDeleteThanks. The Digikey part number for the impedance matching transformer is in the comments section on youtube. I don't have a part number or source for the transducer, since it was just pulled from my shelf of junk. It's probably something like this: http://www.steminc.com/PZT/en/piezo-ceramic-disc-10x2mm-r-215-khz-wire-leads-smd10t2r111wl
DeleteHi there!
ReplyDeleteCould you explain a bit about how the tranformer performs impedance matching? I understand the basics of complex impedances and bode plots, but don't really understand how you can "match" the impediance of a device or what that might do.
For now I've just been playing mine through speaker amps at a really high volume, but that doesn't work too well. My transformer (Digikey MT4148-ND, in case another needs it and the youtube comment disapears) is in the mail.
Thanks so much for all you do!! You've had a great impact on my life and inspired a lot of projects
Jake, thanks for the kind words. Here's an analogy to help understand impedance matching: Suppose you have a 120V tungsten light bulb, and a "D cell" battery. You want to illuminate the light bulb. If you connect the battery directly to the bulb, very little current will flow, and the light bulb will not illuminate. The reason is that the bulb's resistance has been designed to work with a 120V supply, but we are only giving it 1.5V from the battery. The devices are mismatched because they are operating at different voltage levels. The result is that very little power is transferred because of this mismatch. If we had a black box that could convert the 1.5V from the battery into 120V with no power loss, the bulb would illuminate because the voltage level is now matched. The black box could be a transformer for AC circuits because it can match the voltage from one device to the design voltage of another device without losing much power itself. Having a perfectly matched set of devices means that maximum power will be transferred.
DeleteHi Ben,
ReplyDeleteWhat a great video. Keep up the good work!
I got inspired to test this out myself. Can I hook the transformer up to 32 Ohm impedance audio output backwards? Datasheet shows that pri source impedance is 1.6 kOhm and sec load 3.2 Ohm.
All the best,
Bob
This is a very interesting project, and it might be worth giving a tech article presentation at my tech school. Could you please make a video that explains how to create it?
ReplyDelete