Voltcraft VC-840¶
Voltcraft VC-840¶
| Status | supported |
| Source code | serial-dmm |
| Counts | 4000 |
| IEC 61010-1 | CAT IV (600V) |
| Connectivity | RS232 / USB |
| Measurements | voltage, capacitance, continuity, diode, frequency, temperature, current, duty cycle |
| Features | autorange, true-rms, hold, relative |
| Website | conrad.de |
The Voltcraft VC-840 is a 4000 counts, CAT IV (600V) handheld digital multimeter with RS232 or USB connectivity.
Hardware¶
Multimeter:
- Multimeter IC: Fortune Semiconductor FS9721_LP3 (datasheet)
- Low power, True RMS-to-DC converter: Analog Devices AD737J (datasheet)
- Unknown SO-8 chip: ?
- Crystal: likely 4MHz (not verified, though)
- Fuses: 10A/250V and 500mA/250V (one glass fuse, one HRV fuse)
RS232 cable:
USB cable:
Photos¶
Voltcraft Vc840 Pcb Back
Voltcraft Vc840 Device Back1
Voltcraft Vc840 Device Front
Voltcraft Vc840 Device Back2
Voltcraft Vc840 Device Front
Voltcraft Vc840 Battery2
Voltcraft Vc840 Pcb Front
Voltcraft Vc840 Battery1
Voltcraft Vc840 Fs9721 Lp3
Voltcraft Vc840 Ad737j
Protocol¶
See Multimeter_ICs#Fortune_Semiconductor_FS9721_LP3 for the DMM IC protocol.
Depending on the cable, additional decoding is needed, though.
TODO: Serial cable vs. the two USB HID based cables.
A short protocol description is also available from Voltcraft/Conrad. And another one.