Archive for the ‘Control and Monitoring’ Category
Thermoelectric Heat Pump for Laser Diodes Stabilization
Usually, semiconductor laser diodes are operated from current drives. Unfortunately, The output power is strongly dependent on the device temperature – a rise of 15° causes a fall in optical power of (typically) 17% for a given current. Using a feedback loop and monitor the output beam intensity using photodiode is …
Open Loop DC Motor PWM Controller Using NE5560
This is a circuit of the open loop PWM controller using the NE5560. This controller is suitable for Switched mode motor drive. To get the best dynamic response, the switched-mode controller must be set consider to the motor electrical time constant and starting current. The motor has a peak current that must be carried by …[Read More]
A schematic arrangement for a two quadrant controller is shown on figure below. This figure show us the outer speed control loop and the inner current control loop. The tachogenerator derive the speed feedback signal, although alternatively an approximation to the motor speed can be derived by feeding back a signal proportional to the motor …[Read More]
SCR And Triac Triggering Circuit With A Positive Power Supply
The control-circuit output current has to be amplified when the gate current required to trigger the device is higher than the control-circuit output current capability. For example, A lot of MCUs feature output pins with a current capability around 30 mA today. With IGT, they can switch Triacs safely up to 15 to 20 mA. …[Read More]
Overvoltage Protected Compressor Control
We can control medium power load, such as AC motors in home appliances, using ACST12 devices. Because of it’s thermal and turn off commutation performances, this device is able to drive an inductive load up to 12 A with no turn if additional snubber. High thermal performances in static and transient modes such as the …[Read More]
High Side Current Sensing for High Side Switching
Sometimes, there are unexpected solenoid and excessive corrosion occurs on current sense circuit. Corrosive effects can be occurred because of the differential voltage between the ground and the load. To reduce that possibility, the shunt and the switch are placed on the high side. When switch is off, the battery is removed from the load, …[Read More]
High Side Current Sensing for Low Side Switching
An AD8205 can be used to make a high-side current sense with a low side switch. Besides AD8205, an inductive load (solenoid) and a resistive shunt are added in this circuit. The resistive shunt is placed on high-side and the switch is placed on low-side, so that all current measurements, including the the re-circulation current, …[Read More]
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