•  
  •  

Melody generator for greeting cards

This tiny circuit comprising of a single 3 terminal IC UM66 can be built small enough to be placed inside a greeting card and operated off a single 3V flat button cell.
There is not much to the circuit. The UM66 is connected to its supply and its output fed to a transistor for amplification. You can either use a 4ohm speaker or a ” flat” piezoelectric tweeter like the one found in alarm wrist watches.
 
If you use the piezo, then it can be connected directly between the output pin 1 and ground pin 3 without the transistor.
 
The UM66 looks like a transistor with 3 terminals. It is a complete miniature tone generator with a ROM of 64 notes, oscillator and a preamplifier. When it first came into market, it was programmed for the “Jingle bells” tune. Now they come with a wide variety of different tunes.

If there are any problems please contact webmaster@electronic-circuits-diagrams.com

Please share & like

2X(100 Pcs 2N5551 Through Hole NPN Transistors C4E8)
$2.52 2X(100 Pcs 2N5551 Through Hole NPN Transistors C4E8) picture
2X(10pcs Silicon PNP Transistor Amplifier 150V 0.6A TO92 2N5401 U9S1)
$0.99 2X(10pcs Silicon PNP Transistor Amplifier 150V 0.6A TO92 2N5401 U9S1) picture
Triode TFT Backlight LCR-TC1 Tester Diode Transistor Resistor Colorful Display
$16.77 Triode TFT Backlight LCR-TC1 Tester Diode Transistor Resistor Colorful Display picture
10PCS VEMT2023SLX01 NPN PHOTO TRANSISTOR SMD SIDE LO VEMT2023 2023 VEMT2023S 202
$11.29 10PCS VEMT2023SLX01 NPN PHOTO TRANSISTOR SMD SIDE LO VEMT2023 2023 VEMT2023S 202 picture
10PCS TLP785(GRH-TP6,F) OPTOISOLATR 5KV TRANSISTOR 4-SMD TLP785 TLP785( 785( TLP
$10.59 10PCS TLP785(GRH-TP6,F) OPTOISOLATR 5KV TRANSISTOR 4-SMD TLP785 TLP785( 785( TLP picture