Ham radio operators often offer their products in print or on circuit boards. In their manufacture have to drill a large number holes of small diameter (0.8... 1.2 mm). So this work was not too tedious, use special machines, MICROTEL ("drillers"), etc.
This tool requires power. Of course, if you have a laboratory the power supply unit (PSU) or special designed for MICROTEL, there are no questions. And if not? So I felt the need to "PowerLite" and "drills" requires DC voltage 9...18 V At up to 0.5 A. Applying ancient the method of intensification of thinking (chap), appealed for help to computer, more precisely, to its pulsed power supply. Of course, when working PC no one will be connected to the PSU, optional devices, but is off not a sin to borrow a PSU for a while.
There are no words, it is better to take "live" PSU from an old computer gathering dust somewhere on a shelf. Nourish it can be a lot of devices designed for voltage 5... 12 V To absorb excess voltage. if required intermediate values of voltage in the load circuit is sufficient to enable the chain connected to a suitable current of the diodes (the voltage drop across a silicon diode is 0.7 V, the germanium - 0.3 V).
To power MICROTEL I used a computer power supply ATX-230 with output parameters; +3,3 B/10 A; +5 V/20 A, +12 V/6 A; -5V/0.5 A and 12 V/0.5 A.
The pin output connector the ATX PSU-230 shown.
(click to enlarge)
All the nest is connected to the power supply colored wires. The pin assignment of given in the table. Since you have "no load" pulse BP is extreme, should not "tempt fate", and it is better to connect to the PS MICROTEL directly to the contacts 12 In (pin 10 yellow wire) and common (pin 7 - black wire). Enable-disable MICROTEL produced by chain remote control connection output 14 (green wire) to pin 17 (black wire) the Findings wires of the same color. equivalent (interchangeable).
Included PSU in staffing network cord, at its output only appear the auxiliary voltage. Click on the button SA1, mounted on the body MICROTEL (engine starts), and drill. The PSU connection with microdrill is a three-wire cord (common wire load circuits and controls - one and the same). The control of BP is on pin 8 (high logic level all voltages normal BP).
Author: V. Besedin, UA9LAQ, Tyumen