Friday, January 16, 2015

Casontimer HT1-257h 24Hour conversion

Model Clock: HT1-257H
IC:


how: what needs to be done: For this model clock. There is a jumper for 24hour mode.  All that is required is to reflow the solder and install a 10mm long jumper wire as shown below.



  
IC/PCB graphic





Pic 12HR  Pic 24HR


More Mods

Lens for Digital Clock - 7 segment display diffuser
Display Intensity: I would like to at a switch,variable resistor or photo resistor to limit the brightness of the display.

Datasheet:
http://pdf1.alldatasheet.com/datasheet-pdf/view/205672/HOLTEK/HT48R30A-1/+Q0W78WV.MKTGLdlZz./1wvllD+/datasheet.pdf

1 comment:

Unknown said...

Hi, please where does the jumper go? I'm not seeing a complete schematic? Thank you