PS-15 Power Supply
+5V & +/- 0-15V Variable

User Manual

TOMTEC catalog number: ELIC-306
December 2000

By: tomtec at gmail dot com
Student # 800-730-079
Instructor: tumilty at
Class: Elic 306
Semester 3
Fall 2000



Front & Rear Panel Layouts
Power Supply Photo Views
Power Supply Schematic Diagram
Printed Circuit Board Layout
Power Supply Assembly Diagram
Care And Maintenance


This manual is written to give the user a general understanding of how the power supply works and why. It makes use of photographs, schematics and waveform diagrams to illustrate to the reader the finer details of its construction and the expected output under normal operating conditions. It also covers basic testing of the power supply's circuitry and shows the supply's thermal shutdown characteristics.


This power supply is actually three power supplies in one! Built onto one compact circuit are 3 voltage regulators. One regulator (LM780) produces a fixed positive 5 Volt supply. Another (LM317) produces a variable positive 0 to 15 Volt supply. And the last regulator (LM337) produces a variable negative 0 to 15 Volt supply that tracks (LM741) the positive 0 to 15 Volt supply. These regulators are fed fixed DC voltages that are rectified by 4 diodes (1N5402) and then smoothed out by 4 capacitors (037-50102). The center tapped Hammond transformer (166K35) provides the positive and negative 25 Volt sine waves required by the rectifiers. (See Figures 1 and 2 for Front and Rear Panel Views)


Figure 1

Figure 2


For proper operation, the power supply should be connected to a grounded outlet with the provided CSA approved modular power cord. The power supply should never be attached to an extension cord or a power "brick" outlet adapter.


The TOMTEC model PS-15 power supply was designed with convenience in mind. The voltage adjust dial is large to facilitate ease of adjustment, the LCD digital volt meter display is big and bright for clarity, and the main power switches are easy to access. To turn on the power supply, first make sure it is connected to a properly grounded wall outlet with the provided CSA approved power cord. Turn on the digital volt meter's power switch located at the rear of the power supply. Turn on the AC Power ON / OFF switch to the ON position, and adjust the voltage adjust knob until the required voltage is shown on the digital volt meter's display.


Front / Rear

Left / Right

Top / Bottom


Problems ----> Solutions

No Power
-Make sure the power switch is in the ON position.
-Make sure the power supply is plugged into a properly grounded wall outlet.
-Make sure the outlet has power.
-Make sure the fuse isn't blown (both power supply and outlet)

No Voltage Display
-Make sure the Volt Meter power switch is in the ON position.
-Make sure the Volt Meter is connected to a fresh 9 Volt battery.

No +5 Volt supply
-Is the LED ON?
-Yes - external wiring fault, power supply ok.
-No - internal wiring fault, service supply.

No + / - 15 Volt supply
-Is the LED ON?
-Yes - possible regulator failure.
-No - internal wiring fault, service supply.

-If none of these suggested remedies solves the problem, contact your local TOMTEC distributor for assistance.


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Your TOMTEC PS-15 power supply is an example of superior design and craftsmanship. The following suggestions will help you care for the PS-15 so that you can enjoy it for years.

- Keep the power supply dry. If it does get wet, wipe it dry immediately. Liquids can contain minerals that can corrode the electronic circuits.

- Handle the power supply gently and carefully. Dropping it can damage circuit boards and cases and can cause the product to work improperly.

- Use and store the power supply only in normal temperature environments. Temperature extremes can shorten the life of electronic devices, damage batteries and distort or melt plastic parts.

- Keep the power supply away from dust and dirt, which can cause premature wear of parts.

- Wipe the power supply with a damp cloth occasionally to keep it looking new. Do not use harsh chemicals, cleaning solvents, or strong detergents to clean the power supply.

Modifying or tampering with the power supply's internal components can cause a malfunction and might invalidate the power supply's warranty. If your power supply is not operating as it should, take it to your local TOMTEC distributor for assistance.


- Power Supply power requirements: 110/120 Volts AC @ 60 Hz
- Digital Volt Meter power requirements: 9 Volt Alkaline battery
- DC Voltage out: +5 Volts Fixed DC
0 - +15 Volts Variable DC
0 - -15 Volts Variable DC (Tracks Positive)
- Max Current out +5 Volt supply: 581 mA @ 8Ω Load
+/- 15 Volt supply: 1750 mA @ 8Ω Load
- Banana jacks used to connect systems to power supply
- Volt Meter may be used to measure external voltages when power supply main power is switched off. To use this feature, connect voltage to be measured across the Common and +0-15 Volt terminals.
- Case Size: 151 mm X 127 mm Wide X 102 mm High
- Weight: 1.72 kg

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