19-05-2016, 01:40 PM
I found this quote in another forum and hopefully it helps?
Cheers
Adam
I have a couple of Russian meters, mine are model U4324, the one designed for 3 NiCad button cells. The Nicads have long since gone, but the spacing between the battery terminals is an excellent fit for a 6V A21 battery, used in car keyfobs, cigarette lighters, etc, and fairly readily available from Maplins, car accessory shops etc (our local shoe-repair/key-cutting shop sells them for one pound). This battery is also known as MN11 and L1016.
With a 6V battery for resistance ranges, this meter is excellent for testing LEDs, including blue and white LEDs with a 3V forward drop, something AVOs struggle with.
The U4324 has resistance ranges with centre scale values of approximately 500ohms, 5kohms and 50kohms, so with the 6V battery, the full scale currents are 12mA, 120uA and 12uA respectively. Since the meter scale has 6 major divisions, it is easy to read the current in the diode (0 to 12mA etc in the normal forward direction) and voltage across the diode (6V to 0V in the reverse direction). White light LEDs give roughly half scale readings at 3V and 6mA, 600uA or 60uA depending on range, and you can compare light output at these current levels.
The U4324 also has a low resistance range, 25ohms centre scale, but this uses a low voltage (still derived from the 6V battery) with a 12mA maximum current, so this meter is safe to measure sensitive devices such as 1.4V/25mA battery valve filaments despite the high-ish battery voltage.
Stuart
Oh, I forgot to say, the only mod needed to the meter to cope with the higher battery voltage (6V instead of 4V) is to add a 2k2 resistor in series with the ohms adjuster pot, easily accessible with the back removed. Resistance scales are unaffected
Cheers
Adam
I have a couple of Russian meters, mine are model U4324, the one designed for 3 NiCad button cells. The Nicads have long since gone, but the spacing between the battery terminals is an excellent fit for a 6V A21 battery, used in car keyfobs, cigarette lighters, etc, and fairly readily available from Maplins, car accessory shops etc (our local shoe-repair/key-cutting shop sells them for one pound). This battery is also known as MN11 and L1016.
With a 6V battery for resistance ranges, this meter is excellent for testing LEDs, including blue and white LEDs with a 3V forward drop, something AVOs struggle with.
The U4324 has resistance ranges with centre scale values of approximately 500ohms, 5kohms and 50kohms, so with the 6V battery, the full scale currents are 12mA, 120uA and 12uA respectively. Since the meter scale has 6 major divisions, it is easy to read the current in the diode (0 to 12mA etc in the normal forward direction) and voltage across the diode (6V to 0V in the reverse direction). White light LEDs give roughly half scale readings at 3V and 6mA, 600uA or 60uA depending on range, and you can compare light output at these current levels.
The U4324 also has a low resistance range, 25ohms centre scale, but this uses a low voltage (still derived from the 6V battery) with a 12mA maximum current, so this meter is safe to measure sensitive devices such as 1.4V/25mA battery valve filaments despite the high-ish battery voltage.
Stuart
Oh, I forgot to say, the only mod needed to the meter to cope with the higher battery voltage (6V instead of 4V) is to add a 2k2 resistor in series with the ohms adjuster pot, easily accessible with the back removed. Resistance scales are unaffected
