TekPower TP4000ZC
The TekPower TP4000ZC is a 4000 counts, CAT II (600V) handheld digital multimeter with RS232 connectivity.
This multimeter is a rebadged Digitek DT4000ZC.
Hardware
Multimeter:
- Multimeter IC: The microcontroller is an unidentifiable plastic blob (based on the communication protocol, probably a Fortune Semiconductor FS9721_LP3)
- LM358 opamp
- HEF4013BT flip-flop
The RS-232 connector is a standard 3.5m stereo jack, with the ring left unconnected. The transmitter is optically insulated from the rest of the device. The DB-9 connector has a loopback resistor between the RX and TX pins.
Cable:
See Device_cables#Digitek_DT4000ZC_cable.
Photos
Multimeter:
Device, angle
Mugshot
Device, back
Package contents
Holster removed, front
Holster removed, back
Battery compartment
Rear cover
Front cover
Rear cover, PCB removed
PCB, front
PCB, back
Chip
HEF4013BT flip-flop
LM358 opamp
RS-232 optoisolation
RS-232 module
RS-232 PCB, bottom
RS-232 PCB, top
Cable:
See Device_cables#Digitek_DT4000ZC_cable.
Protocol
See Multimeter_ICs#Fortune_Semiconductor_FS9721_LP3.
User bit 2 is used to indicate temperature measurement in degrees Celsius.