What kind of power supply is suitable for the E20 TINI Socket Board? What are the specifications regarding the size of the power supply connector? Is the center pin - or +?
The E20 socket board comes with a built-in voltage regulator. You can use either an AC (50-60 Hz) or a DC power supply. For AC sources, the minimum input voltage is 8 V and the maximum input voltage is 18 V. For DC sources, the minimum input voltage is 9 V and the maximum input voltage is 25 V.The power supply needs to be rated at least 250mA (1.25 watts) to power the TINI SIMM, more for the SIMM plus socket board.
The power supply plug is 5.5mm OD, 2.1mm ID. The center pin may be either positive or negative polarity. A compatible plug is Switchcraft S760K or equivalent. Chances are, you already have a "wall wart" with the right voltage and the right connector from an old external modem, telephone answering machine, or computer speakers. Note that power transformers of this type aren't regulated, so their voltage tends to sag from the nominal rating when attached to a load.