Duocast charge pump alternatives

[dddstudio]

Can I use an ICL7660SCPAZ charge pump in the Duocast?
I do not have any 1054 left.

 

[Sturdag Lagernathy]

Yes, you can.

 

[Matopotato]

Three is a "jumper" SJ1 in the schematic. It is by design/default connecting pins 1 and 8 of the Charge pump as far as I can tell by looking at the pcb. How should the jumper be applied given if you use the "default" LT1054 vs some other charge pump?

 

[jwin615]

As a jumper it is by default open
1054-open
1044, 7660 etc-shorted

 

[Matopotato]

As a jumper it is by default open
1054-open
1044, 7660 etc-shorted

Thanks. Sorry for my confusion, looking at the PCB I see a trace from pin 1 to pin 8 (encircled in green). Looks as if they are connected unless I am getting it wrong...
And DMM confirms pin 1 and 8 are connected.
Still I would have thought as you wrote that it would be shorted to suit LT1054 and the original schematic diagram.

 

[dddstudio]

Thanks. Built it with a 7660 and works alright without any mods.

 

[Robert]

The original idea was to jump the pads for the 7660 / 1044 or leave them open for the LT1054 but it turned out to be unnecessary so it was removed and the pins were permanently connected on the PCB.

You can safely use LT1054, 7660, or 1044 without any other changes to the circuit.

 

[Matopotato]

The original idea was to jump the pads for the 7660 / 1044 or leave them open for the LT1054 but it turned out to be unnecessary so it was removed and the pins were permanently connected on the PCB.

You can safely use LT1054, 7660, or 1044 without any other changes to the circuit.

Thanks a lot Robert!