Washing Machine Diagram / July 20, 2018 / Lena Willingham.
The master timer is realised with monostable IC 555 (IC1) and its ‘on’ time is decided by the resistance of 1-mega-ohm potmeter VR. A 47-kilo-ohm resistor is added in series so that even when the VR knob is in zero resistance position, the net series resistance is not zero.
Remove the adjustment mechanism it's often part of the bracket holding the switch in place! As for identifying the pressure switch, that's easy. Nine times out of 10, it's directly behind the 'water level' adjustment knob in the top control panel of the machine. If the machine's upside down or partly destroyed, follow the sensing tube from the base of the wash tub. And while you're at it, it's also usually worth scrounging the tube, which is often a high-quality plastic hose. You never know when it might come in handy.By contrast, dishwasher pressure switches are normally buried beneath the stainless steel drum.
At times you may feel your laundry is not coming out as clean as it used to be, then also you can doubt the possibility of an error in the heating element. Most probably the clothes might not be getting hot water and consequently they might be getting washed in cold water!
Typically, washing machine pressure switches have a large sensing diaphragm that's about 60mm or so in diameter and three quick-connect male terminals. One connection is common, while the others are for normally open (NO) and normally closed (NC) connections. A set-point adjustment mechanism is built in (it's directly controlled by the 'water level' knob) and the switch opens and closes with audible clicks.