Service manual

12
O p e r a ting Volt a g e
One point which is MOST important is the operating voltage of the Eprom. All those
currently available require a supply voltage of 4.75 to 5.25 volts. A zener stabilized supply
is essential and I would further recommend the use of a transistor series regulator. The
transistor should be rated at 1 Watt minimum, especially for older Eproms whose operating
current could exceed 100 milliamps.
Alternatively, you could use a regulator device, such as a 7805. This is more expensive
than a transistor alone but requires no zener diode or resistor. Regulators are available in
various sizes and ratings from 78L05 (100mA) to 7805 (1A).