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Classic Charger Schematic
Posted by Tony Duell (UK) on 18 Sept 2003, 9:23 p.m.
HP82011 (etc) 'classic series' charger
--------------------------------------
(Unregulated PSU)
-----)||
)||(----+----->|--+-----+------ +16V
)||( | | |
)||( | +-->|--+ === 400uF
Mains)||( | | ---
)||( +--)--|<--+ |
)||( | | |
)||(-------+--|<--+-----+---+
-----)|| |
---
///
(Constant voltage regulator)
c e
+16V ----+------\ >---------------------- +4.2V Logic Supply
| \ / (NPN power transistor)
| -------
/ | b
\ |
/ 470R |
\ |
| |
+---------+
|
---,
^ 4.7V zener
|
---
///
(Constant current charger)
(PNP power transistor)
13R e c
+16V -----+----\/\/\---+--------> /------------- 55mA constant current
| | b \ / charger supply
| ----- -----
| e / \ c | b
+----------> \--------+
(PNP signal transistor) |
/
\ 4k7
/
\
|
---
///