Service
Service
Service
NUDOS NiCd Shavers
HQ 3865/B
HQ 4845/B
HQ 4865/B
HQ 4885/B
Domestic Appliances and Personal Care
Circuit Description
INTRODUCTION
The Nudos shavers with NiCd cells can be recharged in 30 minutes by means of a Fly Back Self Oscillating Power Supply (SOPS).
This electronic circuit enables cells to be recharged at 100-240 V
.
It is possible to shave directly from the mains, provided the voltage exceeds 100V
.
The on/off slide has a locking device, which prevents the shaver from being switched on accidentally. Leaving it connected to the mains after it is fully charged will not damage the shaver.
However, the life of the cells may be shortened if the shaver is kept permanently connected.
If the shaver is kept in the case when charging, make sure that the lid is open to prevent overheating.
HINTS FOR REPAIRS
a. Disassembly
-Remove the shaving unit, to prevent damages during repairs.
-Remove screws A1 (4X, of which 2 are under trimmer slide).
-Put the shaver on the table and remove the cover (item 26) from the shaver.
-The trimmer can be removed by pushing the hinge points (‘Y’ in exploded view, near item 11) slightly inwards.
-Detach the motor clamping springs (item 18) on the bearing block with a small screwdriver.
-The PC-boards with motor can now be removed from the housing.
-Remove screws A2 (2X).
-Unlock the snap connection (3X) between frame (item 14) and hair chamber (item 11).
-If the Power Module (item 23) and Time Control Module (item 7) have to be separated, read the
instructions under IMPORTANT. b. Assembly
-The assembly must be carried out in reverse order of what is described under a. Disassembly.
-The trimmer slide can be snapped into the cover last.
Published by Philips Domestic Appliances and Personal Care Printed in The Netherlands © Copyright reserved Subject to modification
4822 729 22107 97/04 - 99/01
PCS 99 106
NUDOS NiCd shavers |
2 |
TECHNICAL DESCRIPTION
100-240 V 50/60Hz
The electronics for the Nudos shavers with NiCd cells consist of 2 modules:
a Power Module (PM) and a Time Control Module (TCM), connected via a 5-pin connector.
POWER MODULE
The PM consists of a High Voltage Integrated Circuit (HVIC) and some external components, regulating the following functions:
a.a current controller to adjust the charge current at 1200 mA or at 100 mA.
b.a 2.5 V 
dynamic supply controller for shaving from the mains.
c.a primary current limiter (max 400 mA) to protect the transformer from saturation.
d.a frequency limiter (max 60 kHz).
e.an open cell protection (Vbat>5V).
f.a temperature protection (Tchip>140˚C).
The mains voltage is full-wave rectified by D4 and smoothed by π -filter C1-L1-C2.
This filter also serves as a radio interference filter (RIF) for the SOPS and motor and as a suppressor of voltage transients from the mains.
Resistor R1, which functions as a fuse, limits the switch-on (inrush) current and the transient (surge) current.
The resistor interrupts in case of a too large mains current due to improper use or internal short circuit. The primary-current circuit consists of the primary winding of T1 and the high-voltage switch inside the HVIC (IC1).
Snubber circuit D1-D2 limits the voltage across the primary winding during commutation.
During the flyback of the converter (when the switch is open) the secondary winding of T1 will deliver the primary energy across D3 and R2 to the cells or to the R26 sensed motor.
R1
L1 |
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T1 |
D4 |
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C1 |
C2 |
D1 |
C3 |
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D2 |
D3 |
A
2 x AA NiCd
118
217
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3 |
16 |
R5 |
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4 |
15 |
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5 |
14 |
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6 |
13 |
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R7 |
7 |
12 |
R8 |
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R10 |
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8 |
11 |
R12 |
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TS1 |
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C4 |
9 |
IC1 10 |
R9 |
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R14 |
C5 |
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TEA 1402 |
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C6
MP 
MP
1 2 3 4 5
The TCM has 3 variants:
HQ3865 with 4 green LEDs and 1 red/green duoLED. HQ4845 with 1 red LED and 1 green LED.
HQ4865 with 4 green LEDs and 1 red/green duoLED. HQ4885 with LCD, 1 red LED and 1 green LED.
When the PM is connected to the mains, a signal will be generated by the SOPS, which is recognised by the TCM as ‘mains on’.
Depending on the frequency of this signal, the TCM forces the PM into the quick charge mode as long as the capacity counter has not reached the ‘full’ state. After max. 30 minutes the PM is set to the slow charge mode.
If during charging the shaver is switched on, the PM is set to the dynamic 2.5 V mode, in which the control switches from TCM to PM.
With empty cells this means that no charging takes place till the cells reach the 2.5 V
level, consequently the capacity counter is not activated. If the cell voltage is higher than 2.5 V, the motor current will come from the cells.
The capacity counter will now count down, as signalled via R26.
If the voltage drops below 2.5 V again, the PM takes over the supply of the motor current.
TIME CONTROL MODULE
The primary function of the TCM is:
Monitoring the capacity of the cells during charging and discharging.
-controlling the 3 charging modes:
1.1200 mA during max. 30 minutes.
2.100 mA if the voltage across the 2 cells
exceeds 2.5.V and charging exceeds 30 minutes.
3.200-1800 mA at 2.5 V when the motor is switched on at the same time.
During charging and discharging the IC calculates the capacity available in the cells and subsequently generates signals to activate the LEDs and/or LCD, the sequence being:
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