05-10-2023, 02:32 PM
Hello,
I got two HP-67 and a HP-65. The first HP-67 came with a plug-in supply type 82002A (PSU #1) same with HP-65 (PSU #2)
Since all there calculators working (card-reader fixed, resoldering, tantalum-capacitor "cure") I got a odd behavior on PSU #1
Socket / Front
#######################
# #
# 1 ( ) 2 ( ) #
# 3 ( ) #
# #
#######################
-------- PSU #1 -------
Voltage u13 : 1,06 VAC 50Hz
Voltage u23 : 1,57 VAC 50Hz
Voltage u12 : 1,55 VAV 50Hz
The DC amount is
Voltage U13 : -0,678 V
Voltage U23 : 0,061 V
Voltage U12 : -0,001 V
--- PSU #2 --------------
Comparing this to PSU #2 which looks to work
DC:
Voltage U13 : 16,3 V
Voltage U23 : 5,3 V
Voltage U12 : 10,9 V
AC Amount
Voltage u13 : 0,115 VAC 50Hz
Voltage u23 : 0,112 VAC 50Hz
Voltage u12 : 0,030 VAC 50Hz
--------------------
So the PSU #2 has instead of the 4,5 V printed on the PSU 5,3 V - this should be OK since one Jacque Laporte's Page
https://www.jacques-laporte.org/HP3520power20unit.htm
The circuit diagram figure 8 shows a Zener-Diode of 5,1 V - so I assume the Pins 2 and 3 are for the calculator while the 16 V charging the battery with Pin 1 and 3
Which is in my taste at least 3 times to high going through the circuit diagram which shows 4 Volts for both pins.
So PSU #2 maybe usable but I prefer go load the batteries wirth an external charger to avoid damaging something
I replaced in PSU #1 the electrolyte capacitor with 400 mikro Farad - no remedy
Since working PSU #2 has only minimal AC ripples PSU #1 consist only of AC which is strange. I can only imagine that a Diode of the rectifier is broken - but as far as I can see they work (I don't have an oscilloscope - only LCR-Meter and a Fluke 289 Multimeter) - next thing is Zener-Diode but this would explain one one strange VAC voltages at one output - but not the second
Anyone facing the same issue ?
Kind regards
Frank
P.s: I started programming with TI59 in 1981 in school - that's why I choose the Alias :-)
---------
UPDATE
According to EBay auction
Vintage Hewlett-Packard Battery Charger 82002A for Calculators w/Box
the measured Voltage of U12 is 10,94 VDC which matches my findings for PSU #2 - so should be OK.
I got two HP-67 and a HP-65. The first HP-67 came with a plug-in supply type 82002A (PSU #1) same with HP-65 (PSU #2)
Since all there calculators working (card-reader fixed, resoldering, tantalum-capacitor "cure") I got a odd behavior on PSU #1
Socket / Front
#######################
# #
# 1 ( ) 2 ( ) #
# 3 ( ) #
# #
#######################
-------- PSU #1 -------
Voltage u13 : 1,06 VAC 50Hz
Voltage u23 : 1,57 VAC 50Hz
Voltage u12 : 1,55 VAV 50Hz
The DC amount is
Voltage U13 : -0,678 V
Voltage U23 : 0,061 V
Voltage U12 : -0,001 V
--- PSU #2 --------------
Comparing this to PSU #2 which looks to work
DC:
Voltage U13 : 16,3 V
Voltage U23 : 5,3 V
Voltage U12 : 10,9 V
AC Amount
Voltage u13 : 0,115 VAC 50Hz
Voltage u23 : 0,112 VAC 50Hz
Voltage u12 : 0,030 VAC 50Hz
--------------------
So the PSU #2 has instead of the 4,5 V printed on the PSU 5,3 V - this should be OK since one Jacque Laporte's Page
https://www.jacques-laporte.org/HP3520power20unit.htm
The circuit diagram figure 8 shows a Zener-Diode of 5,1 V - so I assume the Pins 2 and 3 are for the calculator while the 16 V charging the battery with Pin 1 and 3
Which is in my taste at least 3 times to high going through the circuit diagram which shows 4 Volts for both pins.
So PSU #2 maybe usable but I prefer go load the batteries wirth an external charger to avoid damaging something
I replaced in PSU #1 the electrolyte capacitor with 400 mikro Farad - no remedy
Since working PSU #2 has only minimal AC ripples PSU #1 consist only of AC which is strange. I can only imagine that a Diode of the rectifier is broken - but as far as I can see they work (I don't have an oscilloscope - only LCR-Meter and a Fluke 289 Multimeter) - next thing is Zener-Diode but this would explain one one strange VAC voltages at one output - but not the second
Anyone facing the same issue ?
Kind regards
Frank
P.s: I started programming with TI59 in 1981 in school - that's why I choose the Alias :-)
---------
UPDATE
According to EBay auction
Vintage Hewlett-Packard Battery Charger 82002A for Calculators w/Box
the measured Voltage of U12 is 10,94 VDC which matches my findings for PSU #2 - so should be OK.