VARIABLE REGULATED POWER SUPPLY MODELS XP-650 / XP-750 Model XP-650 Model XP-750 Instruction Manual Elenco Electronics, Inc. Copyright © 1989 Elenco Electronics, Inc.
Table of Contents Safety Precautions Specifications Operating Instructions Introduction Circuit Description Power Source 0-20V or 0-40V Regulators XP-750 Digital Meters Maintenance and Calibration Variable 0-20VDC Regulator Calibration Variable 0-40VDC Regulator Calibration Digital Meter Calibration on Model XP-750 Parts List XP-650 Parts List XP-750 Schematic Diagram XP-650 Schematic Diagram XP-750 -1- Page Page Page Page Page Page Page Page Page Page Page Page Page Page Page Page 2 2 3 3 3 4 4 5 6 6 6
Safety Precautions CAUTION: When removing cover or replacing fuse, always disconnect the power cord from the AC socket. Service repair should be done by qualified personnel who are knowledgeable of electrical hazards. Certain safety precautions must be observed when this power supply is used with external circuits that are connected to AC power lines. There is always some danger when working with electrical equipment or circuits that operate at hazardous voltages.
Operating Instructions 1. Check the voltage rating of the equipment to be powered. Care must be taken not to exceed this rating. 2. Plug the line cord into a 120V 60Hz AC outlet. 3. Set the voltage switch to 0-20V if the voltage required is under 20V. This assures cool operation of the heat sinks. Adjust the voltage control to the desired voltage. Load variation will have practically no effect on the voltage setting due to the special regulation circuit. 4.
Power Source The power source in both the XP-650 and XP-750 consists of two transformers T1 and T2 and two diode bridges, D1 to D4 and D5 to D8. C3 and C5 are the filter capacitors. Switch S2 places these supplies in series to produce about 50VDC output or in parallel to produce about 25VDC out. A negative 25 volts is produced with diodes D9, D10 and capacitors C1 and C2. This negative voltage is regulated with zener diodes D11 and D15.
XP-750 Digital Meters The Model XP-750 uses two digital meters, one for output voltage and one for output current. The input to the voltmeter comes from a 1000:1 voltage divider, R101 and R102 on the power supply output. Thus, the voltmeter input will be 1mV for a 1V output voltage. Since the meter sensitivity is 10 counts per mV, the meter will read 010. The decimal point is fixed by a jumper wire on the meter so that the output appears as 01.0 volts. The ammeter input comes from a .
Maintenance and Calibration The Elenco Models XP-650 and XP-750 have been designed and manufactured to require no routine maintenance. The circuits are protected by design from external shorts or overloads. The following information is provided in the event the supply requires service or re-calibration. Variable 0-20VDC Regulator Calibration 1) Connect an accurate digital meter to the output terminals. 2) Set the voltage control to the maximum position and switch to 0-20V.
Parts List XP-650 Qty Description Resistors Part # Qty 106803 122200 132000 132201 133300 134700 141000 141001 141200 141800 144700 153900 161000 191516 192413 192511 ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! 4 1 1 1 1 2 2 1 1 1 1 1 1 2 1 1 .68Ω 5% 2W 22Ω 5% 1/4W 200Ω 5% 1/4W 220Ω 5% 1/2W 330Ω 5% 1/4W 470Ω 5% 1/4W 1KΩ 5% 1/4W 1KΩ 5% 1/2W 1.2KΩ 5% 1/4W 1.8KΩ 5% 1/4W 4.
Parts List XP-750 Qty Description Resistors Part # Qty 106803 122200 125005 132000 132201 133300 134700 141000 141001 141200 141800 141801 144700 153900 161000 171000 191516 192413 192511 897120 ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! 4 1 1 1 1 1 2 3 1 1 1 1 1 1 1 1 2 1 1 1 .68Ω 5% 2W 22Ω 5% 1/4W 50Ω 10% 5W 200Ω 5% 1/4W 220Ω 5% 1/2W 330Ω 5% 1/4W 470Ω 5% 1/4W 1KΩ 5% 1/4W 1KΩ 5% 1/2W 1.2KΩ 5% 1/4W 1.8KΩ 5% 1/4W 1.8KΩ 5% 1/2W 4.
160µF 330V -9- 50V 50V Schematic Diagram XP-650
160µF 330V 50V -1050V Schematic Diagram XP-750
WARRANTY POLICY All of our instruments have been tested and conform to our rigid requirements on performance and durability, they are guaranteed to be free of defects in workmanship, materials and construction for a period of 2 years. If this product should fail in normal use within the first 3 months from the date of purchase, Elenco will repair or replace the unit at no cost. For the remainder of the warranty period, a nominal service charge is required to cover shipping and handling.
