MILITARY SPECIFICATION TEMPERATURE CONTROLLERS

Harrel, Incorporated was a pioneer in the development of high precision solid state temperature controllers for military applications. Harrel furnished most of the super high-reliability magnetic amplifier type temperature controllers for the fire control system for the Polaris missile and at least half of the temperature controllers in the missile itself. Harrel was also the first to adapt the silicon controlled rectifier (SCR) for temperature controls very soon after the SCR's introduction in about 1959.

Harrel now offers a complete line of military units, in all power ranges. Most use magnetic amplifier preamplifiers because of their far superior temperature performance and general ruggedness. Integrated circuit preamplifier forms are also available. Operation can be from 60 Hz, 50 Hz, 400Hz, or from d-c.

TC-205 Miniature Temperature Controllers

A series of subminiature units intended primarily for missile and airborne use in applications where weight and size are especially critical.

• Handles up to 500 watts of power.
• 2" x 2" x 1 1/2", weight 7 oz.
• True proportional, SCR output.
• PID temperature control characteristic.
• 780 ohm Ni-Fe or 100 ohm platinum RTD sensing.
• 10-90% output with 0.5 ohms change in sensor resistance.
• 115 volts, 400Hz
• Hermetically sealed and potted for resistance to extreme environments. Vibration and shock per applicable MIL specifications.

TC-200 SERIES PROPORTIONAL TEMPERATURE CONTROLLERS

Designed for very close temperature regulation of high precision floated gyros, delay lines, test fixtures, and other military equipment, where temperatures must be maintained to very close tolerances and where long life and reliability are of the utmost importance. Magnetic amplifier preamps give best reliability and resistance to environmental extremes, while SCR power control gives high efficiency control of power output.

• True proportional output; PID control.
• Rugged -- withstands most severe environmental conditions.
• Small size - 2 1/8" x 2 1/4" x 2 1/4"
• Two forms -- 500 watt or 2000 watt output.
• MIL spec noise filtration optional.
• 780 ohm Ni-Fe or 100 ohm platinum RTD sensing.
• 115 volt 60 Hz or 400 Hz.
• 0.29 or 1 degree C prop band.
• Hermetically sealed and potted for resistance to environmental conditions.

TC-204 ULTRA-HIGH SENSITIVITY PROPORTIONAL TEMPERATURE CONTROLLERS

A very high gain series for use in applications such as delay lines, quartz crystals, oil baths, etc., where even closer regulation of temperature is required than afforded by the TC-200 series controllers. May be mounted inside the volume being controlled for highest possible stability.

• 115 volts, 60 Hz
• Power output 500 watts. More on special order.
• 780 ohm Ni-Fe or 100 ohm platinum RTD sensor
• 10% to 80% output variation for 0.05 ohm change in sensor resistance.
• 6" diameter x 1 1/2" high. Rectangular shapes also available.
• Ambient temperature -55 to 85 C

TC-700 SERIES NOISE-FREE TEMPERATURE CONTROLLERS

Similar to TC-200 units, except output generates no radio frequency interference. Employs a system of pulse width modulation power control which approximates true proportional action -- so-called time proportioning.

• Generates no radio frequency interference on power lines.
  
• Other specifications same as TC-200 units.

TC-203 Series Proportional Temperature Controllers -- pure d-c output

A series of proportional temperature controllers designed for use on gyro test tables or in laboratory installations. Same high efficiency and close temperature control as TC-200 units, but the signal delivered to the heater is d-c with less than 5% total ripple.

60 Hz model:

• Input 115 v, 60 Hz
• Output 115 volts d-c or 28 volts dc, selectable
• Output current 1.7 amperes
• Sensitivity 10% to 90% output for 1 ohm change in RTD sensor.
• Sizze 7" x 7" x 5 1/4"

400 Hz Model

• Output 90 v d-c, 100 watts
• Input 115 volts, 400 Hz
• Ambient temperature -55C to 85 C
• Vibration and shock per MIL specs
• size 2 5/16" x 2 5/16" x 5"

TC-202 Proportional Temperatue Controllers -- D-c operated.

These controllers aae similar to the TC-200 units except that they operate completely from d-c power. D-c in and d-c out.

• Input power; 28 volts d-c.
• Output 0-26.5 volts d-c.
• Sensitivity 10% to 90% for 0.2 ohm change in sensor resistance
• Ambient temperature -55 C to 71 C.

For more information, please fill out our inquiry form or call Harrel at (203) 866-2573.

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