Here we have a Dremel MultiPro rotary tool, a main powered 125W 33,000RPM bit of kit.
Here the field & controller assembly is removed from the casing.
Here is the armature, which rotates at up to 33,000RPM. The brushes rise against the commutator on the left, next to the bearing, the cooling fan is on the right hand side on the power output shaft, the chuck attaches at the far right end of the shaft.
Here is the speed controller unit, inside is an SCR phase angle speed controller, to vary the speed of the motor from 10,000RPM to the full rated speed of 33,000RPM.
This is the mains filter on the input to the unit, stops stray RF from the motor being radiated down the mains cable.
Here is a phone from the mid 90s, the Ericsson GA628. Here visible is the front of the unit with keypad, & single line monochrome LCD for number display.
Here the battery is removed from the phone, showing the SIM card socket. At the top under the antenna stub is the socket for an external antenna.
Here the front is removed from the phone, PCB on left, rear of keypad on right. Microphone is at bottom of keypad, with speaker at the top. Top right of the PCB is the ringer buzzer, left is shield for RF amplifier.
Here is the back of the main PCB, RF sections on left & centre. Processing & memory on right.
This phone had a Ni-Mh battery, before Li-Ion batteries were introduced.
The LCD from the front of the phone is shown here. A simple dot matrix single line unit.
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