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MR-50 Adapter - Voltage Reducing Converter

Type: Voltage reducing adapter kit

Contents: Kit contains 1 x MR-50 Adapter, 1 x 357 cell. Output Voltage: 1.35 V.

Diameter: 15.4 mm. Height: 16.5 mm. (including silver-oxide cell)

Price: £29.43 each. Postage and packing included.

Emulates: Eveready E1N / Mallory RM-1N / PX1 / MR50 / RPX1 / EPX1 / RM1 / RMIN / V1PX / H-P / Leclanche MR85 / ISA-MR850 / NR50 / HD1 / HP.

The "Rolls Royce" solution to problem of the discontinued Mercuric Oxide MR50 and PX1. Our MR-50 Adapter has the outer dimensions of the PX1  mercury cell with a recess that takes the inexpensive and easily obtained silver oxide 357 cell. Buried within the MR-50 Adapter are micro electronics that drop the voltage from the 1.55 Volts put out by the silver oxide cell to the 1.35 Volts that your  camera was designed for.

No adjustment or modification to your camera is required. The MR-50 Adapter does not require activation or a supply of air.

MR-50 Adapters are a one time purchase, and will last a lifetime. Simply replace the expired silver oxide 357 cell with a fresh one.



The MR-50 Adapter is designed for low current and cannot be used in applications that exceed 200 micro amps. There are no known examples with this adapter though there are two examples involving the similar MR-9 Adapter where the metering and exposure system function perfectly, but the battery check lamp will not illuminate.

If you wish to measure the voltage from the MR-50 Adapter and silver oxide cell with a digital voltmeter, put a 10 KiloOhm resistance between the measurement terminals. This will allow sufficient current to flow to activate the voltage reducing circuitry. An analogue voltmeter will draw sufficient voltage to activate the voltage reducing circuitry.

Click here to purchase extra 357 cells.

There is another possible mercury free replacement for a PX1 or MR50 cell:
An inexpensive PX1 replacement is the alkaline cell, the LR50 or A1PX. They fit perfectly but, as with all alkaline cells the voltage is not stable, it drifts down from 1.5V towards 1.35V (the voltage of the original Mercury cell) and then lower still. If you use the cell in a camera that needs a steady reference voltage, as the voltage is not steady throughout the useful life of the cells,  you need to constantly adjust how you compensate.

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