24 Aug
2013
24 Aug
'13
3:56 p.m.
On 2013 Aug 24, at 12:29 PM, Fred Cisin wrote:
>> The battery pack of the TI Programmer has a
clip like a 9V
>> battery. IS IT
>> 9V, or just using that connector?
...
The wallwart says 5.7VAC.
One of them has a BP-5, instead of a BP-8, which takes a slightly
different external power input connector.
In the BP-8 (rechargeable battery pack), the 5.7VAC from the wallwart
goes through a single diode rectifier and is dumped across 2 NiCd
cells (no limiting resistor, the wallwart internal R is providing
current limiting).
The ~ 2.5V from the NiCds feeds a simple boost converter (an IC, R, C
and L) to supply ~ 7.5 to 9V to the calc on the '9V' clip.
The calculator alone (fed from the '9V' clip) will function down to ~
5V.