•  
  •  

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

EEPROM BIOS usb programmer CH341A + SOIC8 clip+1.8V adapter + SOIC8 adapter uq
$13.06 EEPROM BIOS usb programmer CH341A + SOIC8 clip+1.8V adapter + SOIC8 adapter uq picture
Koyo, PLC Direct | D4-EE-2 | EEPROM 32KW (Refurbished)
$72.0 Koyo, PLC Direct | D4-EE-2 | EEPROM 32KW (Refurbished) picture
10PCS W27C512 W27C512-45Z DIP IC EEPROM 512KBIT 45NS NEW
$5.65 10PCS W27C512 W27C512-45Z DIP IC EEPROM 512KBIT 45NS NEW picture
Hour Meter Gauge With EEprom Memory Storage No Battery (60-275 AC/DC Volt)
$8.0 Hour Meter Gauge With EEprom Memory Storage No Battery (60-275 AC/DC Volt)  picture
High Speed USB SPI Programmer Support 24 25 93 EEPROM Flash Bios Chips EZP2019
$7.89 High Speed USB SPI Programmer Support 24 25 93 EEPROM Flash Bios Chips EZP2019 picture