Peanut and melon seeds roasting machine circuit

When small and medium-sized oil factories in rural areas use small oil-pressing machinery, they need to first use a fire kang or a flat-bottomed wok to process oil crops (including soybeans,
peanuts , rapeseed, cottonseed, sunflower seeds, sesame, corn germ, rice bran, etc.) ) blanks are roasted or steamed to improve the oil quality and oil yield
. Due to the high temperature near the baking and frying equipment, it is very difficult for the staff to operate at close range. If the oil crop roasting and frying machine controller introduced in this example is used,
remote control of the roasting and frying equipment can be achieved.
    (1) Circuit composition The oil crop roasting machine controller is actually a single-wire remote forward and reverse control circuit for the motor
. The relevant circuit is shown in Figure 8-21.
  Fuse FU3, power transformer T, control switch S and diodes VD1, VD2 are controller circuits installed in the operating room; motor
M, knife switch Q, fuses FU1, FU2, AC contactors KM1, KM2, relays Kl, K2 , capacitance Ci. C2 and diodes
VD3 and VD4 are the stirrer drive circuit of the roasting machine installed in the roasting workshop; the controller and the stirrer drive circuit of the roasting machine
are connected through a control line.
    (2) Circuit principle: After the 220V AC voltage is stepped down by T, a 36V AC voltage is generated on its secondary winding, which is used as
the working power supply of relays Kl and K2. When S is placed in the "1" position, neither Kl nor K2 works.
    When in use, the knife switch Q should be turned on first, and then S should be turned on to control the forward and reverse rotation of the motor M. When S is placed in the "2" position,
the 36V AC voltage of T's secondary winding forms a loop through VD1, ground wire, earth, VD3, and Kl, causing Kl to be energized and closed, and its normally open contact is connected
. KM1 pulls in, the motor starts to rotate forward, and drives the mixer (composed of scrapers, etc.) to work. When S is placed in the "3" position, 36V
AC voltage is applied to K2 through VD2, ground wire, earth and VD4, causing K2 and KM2 to attract, K1 and Kvn to release, and the motor M
drives the stirrer, etc. to run in reverse.