The battery pack goes to the other remaining pin on the toggle. Another wire connects the other outside pins on the toggle and this wire has the microswitch in-line. A short length of wire connects opposite pins on the toggle. Wire the gear motor to the indicated pins. Follow the directions carefully or purchase the Useless Printed Circuit Board from us to speed up and greatly simplify the wiring process. It's a very simple circuit but it's easy to mess up the wiring. This is called 'Dead-Bugging' and is a prototyping method from way back. The diagram above indicates how you will wire the motor, micro-switch and battery pack to the pins on the toggle switch. He also pointed out that it's better to use "4 fresh alkaline batteries-with 4 rechargeables, I couldn't depend on having enough power to always throw the switch." ![]() Mrrigsby reports that a toggle switch from Radio Shack, catalog # 275-636 works. ![]() Most of the standard servos should do the job. Keep in mind that the toggle switch and arm length are some of the things that will determine how strong a servo you’ll need. A standard size servo with at least 4-5Kg/Cm torque will work in most cases. Stay away from any of the micro-sized servo’s. It's a standard size servo with a torque of 55.0 oz-in. If you use a Parallax continuous rotation servo there is no need to modify the gears, but you will have to modify the wiring to the servo's motor. Or you can modify a standard RC servo for your geared motor: Here's the parts you need to build the Useless Machine:īattery Holder 2-AA Cells (Note: 3 AA's or even 4 AA's will work, faster, maybe too fast ) DPDT Toggle Switch SPDT Micro-Switch (Just about any with 3 pins and a lever should work.) This type of switch is actually a pair of switches which operate together (Dual Pole) and both are On-On (Dual Throw).įrivolous Engineering buys parts from Newark/Element 14 & you should too! The toggle switch needed is a Dual Pole, Dual Throw (DPDT) toggle switch. When the arm runs into the micro-switch it stops. The arm reverses direction returning towards it's 'OFF' position. When the toggle gets switched “OFF” it actually reverses the motor’s direction. As the arm moves away from it's off position it releases the micro-switch providing the backup power needed for the motor to retract after the toggle switch is turned off. When a person turns the toggle switch to the forward position, it also provides power to the motor causing it to rotate the arm towards the toggle switch. By using the common pin and the normally closed pin the micro switch is “OFF” when it’s button is being pushed. Keep in mind the micro-switch is wired up so that it works completely opposite from a normal switch like you would find in a doorbell. The toggle is “Reverse” direction, and the micro-switch is being held in the off position by the servo arm. When idle, the circuitry is fully powered down. The toggle causes the motor to reverse, while a micro-switch powers down the circuit when the arm finishes retracting back into the box. The switches are positioned to be limit switches for the motorized arm. ![]() Inside the box is an geared motor powered by double A batteries and two switches: a toggle switch on the top of the box and a micro-switch inside.
0 Comments
Leave a Reply. |