# Week 9. Output Devices¶

Group Assignment: Measure the power consumption of an output device.

• As part of our group assignment, we needed to figure out how much power our output device was using. We chose to measure the power across the Small Push-Pull Solenoid - 12VDC.

• To do this, we first went through the Technical Details of the Device.

• 12 VDC operation (please note lower voltage results in weaker/slower operation)
• 250mA current draw
• Push or pull type with 5.5 mm throw
• DC coil resistance: 40 ohms
• Newton starting force (12VDC)
• 1.4 oz / 39 grams
• we initially calculated the power consumption based on the specifications provided in the datasheet.

``````Power = Current x Voltage
P = 12V x 0.25A
P = 3 watts
``````
• Afterward, we conducted practical measurements using instrumentation, as depicted in the image. This allowed us to compare the calculated power with the actual power drawn by the Small Push-Pull Solenoid - 12VDC. By doing this, we could see both the voltage and the current. This helped us understand power consumption of the device.

``````From the practical measurement:

Output voltage = 11.7 V
Current = 0.27 A
Power = 3.16 W
``````
• Additionally, we explored the effect of supplying the solenoid with 9 volts instead of the required 12 volts, which resulted in a slower operation of the solenoid.