UNIVERSITY OF CALIFORNIA Los Angeles - Users - UCLA

Figure 59. Two weeks running test
12 motors (KH56KM2) with 3arduinos and 1 power supply (3V/40AMP)
Figure 60. NPN
transistor
Washer Pump To control salt water, windshield washer pumps for cars
are used. They usually require 12V of electricity to function, but 5V of
power was enough to pump water up to 4 inches from underneath of an
aluminum sheet.
Figure 61. Tip 120, an NPN transistor, with diode (1N5399) was used to control the
amount of water and time for the pump.
Figure 62. Windshield
washer pump
manufactured by
CRP-Contitech/Meyle.
Special Electrical Needs of Motors (power supply) Like other
motors, stepper motors need more power than the arduino type of
microcontroller. Because motors draw so much current when they start
up, they affect the current going to the circuit that controls them. To
avoid this problem, I used bigger power supply than required because the
efficiency of power supplies may be lower than the labeled description.
Some tips I learned during the creation of my installations are (1) use
regulated supplies, which ensures that the voltage will not drop as the
current increases (2) use switching supplies which are more efficient than
linear ones; however, depending on the product, SMPS’s (Switching
Mode Power Supplies’) efficiencies vary, and (3) use decoupling capacitors.
J.KIM_A LANDSCAPE OF EVENTS 53