For normal operation multimeters series M830 need power supply 9 V (battery type 6F22 or her similar). Multimeter works great when the voltage to 7.5 V. However, in the fall voltages below this value, the measurement accuracy decreases, while the voltage less than 6 In the multimeter is not able to measure.
For accurate measurement parameters with a multimeter it is necessary that the voltage was constant.
For this propose to use the well-known chip type SEPIC, for example, company Linear Technology. On Fig.1 shows a diagram of the voltage Converter is recommended firm for chip LT1308.
The device is made on the PCB size 10x10 mm (Fig.2).
The Pinout of the chip and LT1308 its dimensions are shown in Fig.3.
Chip select is that it gives you the chance to get the voltage (9 V) from a single lithium-ion battery throughout its "life". Even when the voltage of the battery 1 In the chip is able to "pull" on the output of the circuit to about 9 V.
In this scheme can also use NiMH or LiON batteries size AA any capacity. These batteries with the power circuit freely placed in the battery compartment of the multimeter. In this case, batteries can be recharged repeatedly.
Author: P. Bobonich, Uzhgorod, Ukraine