Assembly of your M-2666K Digital Multimeter Kit will prove to be an exciting project and give much satisfaction and personal achievement. If you have experience in soldering and wiring technique, you should have no problems. For the beginner, care must be given to identifying the proper components and in good soldering habits. Above all, take your time and follow the easy step-by-step instructions. Remember, “An ounce of prevention is worth a pound of cure.
A block diagram of the M-2666K is shown in Figure 1. Operation centers around a custom LSI chip. This IC contains a dual slope A/D converter, display, latches, decoder and the display driver. A block diagram of the IC functions is shown in Figure 6. The input voltage, current or ohm signals are conditioned by the function and selector switches to produce and output DC voltage between 0 and +199т. If the input signal V Voltage V Divider Q Ohms Q Converter AC Converter mA Current Shunts Range Switches VAC VAC/mA AC, mA is 100VDC, it is reduced to 100mVDC by selecting a 1000:1 divider. Should the input be 100VAC, then after the divider it is processed by the AC converter to produce 100mVDC. If current is to be read, it is converted to a DC voltage via internal shunt resistors. For resistance measurements, an internal voltage source supplies the necessary 0-199mV voltage to be fed to the IC input.