Vernier Software and Technology
Vernier Software & Technology
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Where do I find electronic components for use with the Digital Control Unit (DCU)?

The Digital Control Unit, order code DCU-BTD, $61 can be used with any DC electronic component or output device that requires only power and ground connections, such as an LED, buzzer, or fan. Take care to match the DCU power supply to the output devices. For instance, a 12V DC fan will run slow when connected to a DCU running on the standard (5V) LabQuest Power Supply, order code LQ-PS, $11. Likewise, you will likely burn out a 5V fan if the connected power supply is 12 V. Note: Most LEDs are designed to operate on 2-3 V and 10-20 mA. When using one with the DCU, you'll need to use a resistor to limit the current through it.

Electronic components can be found at a variety of online and brick-and-mortar stores. The best supplier for solenoids, stepper motors, and other parts is usually a local reseller of used electronic parts. Check your local area for surplus stores. They are cheaper and much more fun to rummage through than a catalog.

We sell a few electronic components compatible with the DCU:
* KidWind Small Water Pump with Tubing, order code KW-PUMP, $11
* KidWind Wind Turbine Generator with Wires, order code KW-GEN, $7 (Note: Although labeled as a generator, it can also be used as a motor.)
* KidWind Power Output Pack, order code KW-POP, $14 (Note: Use a resistor with the LEDs, as mentioned above.)
* KidWind Sound and Light Board, order code KW-SLB, $9 (Note: Resistors are wired into this board with the LEDs, so no additional resistors are required.)
* Digital Control Unit Power Output Kit, order code DCU-POP, $35

Below is a list of some national online suppliers:
* SparkFun (
* Mouser Electronics (
* Electronix Express (
* Jameco Electronics (
* Parts Express (
* All Electronics Corp. (
* Edmund Scientific (
* Digi-Key (

Other devices can be operated via the DCU with some extra hardware and/or software:

* A LabVIEW or Arduino program can control the DCU and, when doing so, can operate all six digital lines as well as allow pulse-width modulation (PWM) on line 4. This extra functionality allows you to control the motion of a servo motor and the speed of a DC motor. Likewise, a LabVIEW or Arduino program could control the DCU lines to drive a stepper motor.

* SparkFun Servo Trigger - The DCU can use this simple control board to move a servo motor from one pre-determined position to a second pre-determined position (or back), by setting the Trigger's input line high (or low). With this Trigger and the DCU, you can operate a servo motor straight from Logger Pro. The Servo Trigger can be found on the SparkFun website.


DCU connected to the SparkFun Servo Trigger - when DCU line D1 is activated, servo will move from one position to another

* PowerSwitch Tail II - This power cord can switch on and off 120 V, AC devices with a simple control voltage, like the output of DCU or Arduino. More details can be found here:

TIL 2101: Digital Control Unit (DCU) Troubleshooting and FAQs
TIL 4224: DCU Power Output Pack (DCU-POP) Troubleshooting and FAQs

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