Solderman Basic Electronics

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Thursday, December 18, 2008

Single Set Point Temperature Controller

This is a generic or standard controller for any type of process. Shown here is a temperature controller.

The STC1000 could be used for Ovens or furnaces, liquid baths, heating or environment chambers. It has a single analog input and an analog or relay output.

Temperature Controller

Process Control Instrumentation Section Updated

Analog inputs could be like 4-20 mA, thermocouple or RTD. Analog outputs can be 0-10 V for a thyristor drive, SSR drive output or potential free contacts of a relay to operate external 3 phase contacters.

Saturday, December 13, 2008

Capacitor Temperature Monitor

When placing sensors in high pressure or vacuum chamber, they should be terminated by an epoxy sealed terminal block interface on the system. 4 wire RTD is best for such applications, as multiple terminations and junctions are involved; also the wires may have to run some distance.

When measuring temperature in a big surface or object, use multiple sensors. An indicating scanner-controller can be used or ensure cooling-heating is uniform using fluids or air circulation.

Zoom Image

Cooling Controller


RTD Sensors to Terminal Block Connections

W - is White Wire from RTD, R - is Red Wire from RTD, Color of Wire on RTD Sensor Pt-100.
Top 3 Terminals are for RTD 1 (Red), Bottom 3 Terms. are for RTD 2 (Yel), Marked with Color Tape.

The RTD two whites go to one end of the Platinum 100 ohms resistive sensor, the red goes to other end. The red in this sensor goes to gnd of opamp circuit in controller. Thru one white a 1mA current is injected, the other white gives a voltage output to opamp. This voltage after offset and calibration is proportional to temperature.