Last updated: 21 June 2002
Subject: Yet another power supply for ETX 70 Sent: Wednesday, June 19, 2002 3:13:01 From: email@example.com (bob greef) The six AA Batteries just don't last long enough on the ETX 70, I have had pointing accuracy problems with both NiCD and NiMH rechargables as they only deliver 1.2 Volts each and a mains adapter is of very little use in the field. My own solution is a small 12 volt sealed lead-acid battery connected to the ETX via a regulated DC-DC converter that supplies a range of voltages from 3V to the full 12V. The connection to the ETX is via a standard 2.5mm power plug that plugs into a standard 2.5mm socket fitted to the lid of the battery compartment. The socket is in turn connected to the normal ETX battery connector via a further PP9 type connector. This all means that the only alteration required to the telescope itself is the drilling of a small hole in the battery compartment lid to accept the 2.5mm socket. Removal of rhe battery compartment lid allows a return to normal six X AA batteries use if required. I have been using this mod since January with no problems, the converter, plug and socket, lead-acid battery and various connectors are all available off the shelf, (in the UK at Maplins Electronics but I am sure that Radio Shack would carry a similar range)total cost about £20 UK including the battery. I usually just sit the Battery and Converter on the Eyepiece tray during use. I would recommend frequent checking of polarity during assembly, I used a cheap multimeter. Photographs attached which may explain better. Hope this helps someone: Super Site! Bob Greef Norwich England
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