3
\$\begingroup\$

Like many of us, the buzzer in my dryer is loud as hell. I recently opened up my dryer to repair it and easily found the buzzer and simply disconnected it. However I got to thinking: Could I replace the buzzer with something less obnoxious...like a piezo buzzer? Most piezo buzzers I’ve seen are DC and low voltage. And the buzzer from my dryer is rated at 120V. Would there be any easy way to rig up a piezo buzzer as a replacement for the buzzer in my dryer?

\$\endgroup\$
  • 5
    \$\begingroup\$ put tape over the buzzer hole \$\endgroup\$ – Tony Stewart Sunnyskyguy EE75 Mar 12 at 4:20
  • 1
    \$\begingroup\$ Put a 120V relay where the buzzer was, switch a low-voltage circuit on the piezo. Remember to use an AC coil if your 120 V is AC. \$\endgroup\$ – jonathanjo Mar 12 at 4:40
  • \$\begingroup\$ Hmm.. ours (older Kenmore Elite natural gas) has a 3-position switch to control the buzzer (off/low/high)- maybe find out how they do it. I always keep it on high because otherwise.. wrinkles (even with the intermittent run during cooling). \$\endgroup\$ – Spehro Pefhany Mar 12 at 12:49
  • \$\begingroup\$ use a transformer to half the voltage to the buzzer, which should make it 75% quieter. \$\endgroup\$ – dandavis Mar 12 at 20:16
  • \$\begingroup\$ Does just sticking a resistor in series with the buzzer work? \$\endgroup\$ – DKNguyen Mar 19 at 18:35
5
\$\begingroup\$

Got a brilliant idea from one of the EE's at work... iPhone wall adapter as AC/DC converter. Plug tongs fit inside the clips that connected the previous buzzer. USB cable cut and wired to Piezo. The iPhone adapter outputs DC, drops the voltage to 5V which the Piezo can handle, and it work like a charm. My wife can't understand how I did it. I'm a champ (for a day).

dryer piezo

\$\endgroup\$
2
\$\begingroup\$

As Sunny said, tape over the hole is the easiest option.

The next thing I would try is adding a power resistor in series with the buzzer. The issue is, you need to know approximately how much current the buzzer draws.

I found a couple online, and it looks like 5-15W is a safe bet.

https://www.searspartsdirect.com/product/1ev8sv2nmu-0026-110

Wow that's a lot, anyway...

Now, I'm not 100% sure here, so anyone please correct me if I'm wrong, but according to this source, you need to reduce the wattage to approximately 1/100th to perceive 1/4 the loudness.

That means you want to reduce 10W to 0.1W, maybe the buzzer won't even work at that level.. but lets continue. The formula is W = V^2/R, R is fixed (that's the buzzer impedance), and we know we want W to be 1/100th of what it was, so that means V will be reduced to 1/10th or 12V. The impedance of the buzzer is 120^2/10 = 1440 ohms. At 12V we'll be pulling 12/1440 = 0.0083A. We need to drop 108 volts, so 108/.0083 = 13k. And the wattage will be 108*.0083 = 0.896W

So TLDR; I'd try a 10k 2W power resistor in series and see what that does.

\$\endgroup\$
  • \$\begingroup\$ Yes, I'd try the resistor solution. You aren't sure of the power draw of the buzzer, and it may not have a predictable response anyway, so I'd get a few resistors to play with (1k, 5k, 10k) of appropriate power ratings. As long as they're in series with the buzzer it shouldn't hurt anything. And, if the buzzer somehow gets damaged, you were choosing to disable it anyway! \$\endgroup\$ – bitsmack Mar 12 at 7:14
  • \$\begingroup\$ @bitsmack You could just use a trimpot. \$\endgroup\$ – forest Mar 12 at 8:07
  • \$\begingroup\$ Inline resistor is a great and simple idea! Going to play around with that. I’ll report back with results. Thanks! \$\endgroup\$ – Elliott Samuel Lemberger Mar 12 at 14:15

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.