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The 106LVPS-1, 106LVPS-2, and the 106LVPS-3 Low Voltage Power Supply printed circuit boards (PCBs) are simple (KISS) temperature compensated low voltage power supplies for use in a wide range of logging tools. All three circuits are diode protected against reversed polarity accidents; feed-thru power can be configured for either polarity, diode protected or unprotected.
The 106LVPS-1 Low Voltage Power Supply PCB uses a ten volt zener diode (D3) and three forward junction diodes (D-4 through D-6) to produce approximately 12 volts of output. This scheme produces a simple temperature compensated power supply due to the opposing temperature coefficients of the two kinds of diodes employed. This is the same little circuit used as the temperature compensated power supply in the pulse version of the old GO (Well Reconnaissance) 1-1/4 inch three arm caliper. Voltage regulation is better than .005% per degree to 200°C (400°F), much better than an uncompensated zener supply and good enough for the majority of downhole tool applications. Selection of the value of the chassis mounted series resistor (R1) sets operating current and line voltage; two (2) kilohm results in about 54 milliamps at 120 volts or close to the standard 60 milliamps at 120 volts with a typical downhole CCL amplifier also connected. The 106LVPS-1 PCB is jumper configurable to run off either armor / chassis negative or armor / chassis positive line power. The 106LVPS-1 PCB measures 0.8 inches wide and mounts on two (2) inch centers.
The 106LVPS-2 Low Voltage Power Supply PCB uses three series zener diodes (D3 through D5) to produce approximately 15 volts of output. This scheme produces a simple temperature compensated power supply due to the opposing temperature coefficients of the two values of zener diodes employed. Voltage regulation is much better than an uncompensated zener supply and good enough for the majority of downhole tool applications. A five (5) volt output is also available if same is needed to power logic or other circuits. Selection of the value of the chassis mounted series resistor (R1) sets operating current and line voltage; two (2) kilohm results in about 52 milliamps at 120 volts or close to the standard 60 milliamps at 120 volts with a typical downhole CCL amplifier also connected. The 106LVPS-2 PCB is jumper configurable to run off either armor / chassis negative or armor / chassis positive line power. The 106LVPS-2 PCB measures 0.8 inches wide and mounts on two (2) inch centers.
The 106LVPS-3 Low Voltage Power Supply PCB uses three zener diodes (D3 through D5) to produce both 10 volts and 15 volts of output. The 15 volt output is not temperature compensated, but the 10 volt output is derived from a pair of zener diodes which can have different temperature coefficients, allowing tailoring and compensation of the 10 volt output temperature coefficient. The 106LVPS-3 also decouples and further filters the 10 volt supply. A five (5) volt output is also available if same is needed to power logic or other circuits. Selection of the value of the chassis mounted series resistor (R1) sets operating current and line voltage; four (4) kilohm results in about 25 milliamps at 120 volts. This low operating current is ideal for temperature tools where it is good engineering practice to avoid excess heat dissipation inside the tool. Selection of a two (2) kilohm resistor for R1 results in about 52 milliamps at 120 volts or close to the standard 60 milliamps at 120 volts with a typical downhole CCL amplifier also connected. The 106LVPS-3 PCB is jumper configurable to run off either armor / chassis negative or armor / chassis positive line power. The 106LVPS-3 PCB measures 0.8 inches wide and mounts on two (2) inch centers; the 106LVPS-3n PCB is designed for one inch diameter tools and is only 0.6 inches wide and mounts on two (2) inch centers.
The 106LVPS-1, 106LVPS-2, and 106LVPS-3 Low Voltage Power Supply PCBs are part of the 106 Radiation Tool™ PCB family. 106 Radiation Tool PCBs can be used to upgrade or repair tools, or an entire electronics section can be assembled from scratch using several PCBs (as in reworking an old tube / Nuvistor tool). All 106 Tool PCBs use readily obtainable components, which parts will continue to be available for many years to come, and all use convenient turret terminals for wiring connections. We prefer through-hole components for PCBs designed to survive high temperature, but selected components may be surface mount (SMT), or have provisions for either through-hole or SMT where price and/or availability is an issue. Due to time constraints on maintaining this website, the PCBs illustrated below may not be the most recent revision of the boards and / or circuits.
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