Selection of thermal cut-off switches
The working principle of bimetallic thermal cut-off switches and thermostats of SPST and SPDT. Its inner and outer layers are made of two metals with different thermal properties. When the temperature changes, the free end of the bimetallic piece will contact or separate from the static contact piece next to it. Therefore, automatic temperature control of the circuit can be achieved using bimetallic sheets. As shown in Figure 2, it is the circuit schematic diagram of an electric water dispenser for students in a certain classroom. Among them, S0 is a bimetallic temperature control switch. After analysis, it is known that the electric water dispenser has two working states: heating and heat preservation. When S is closed and S0 is open, the water dispenser is in a heat preservation state. When S and S0 are closed at the same time, the water dispenser is in a heating state. but:
(1) The bimetallic temperature control switch works by utilizing the thermal expansion and contraction properties of metal.
(2) When the water dispenser is in heating state, R1 and R2 are connected in parallel.
(3) If the pointer of the ammeter is at the position shown in Figure 3 during heating and heat preservation, what are the currents flowing through R1 and R2 during heating?
(4) How many coulombs of charges pass through R1 and R2 after heating for 3 minutes?
Metal expansion thermal cut-out switch
According to the principle of thermal expansion and contraction of objects. Thermal expansion and contraction are common characteristics of objects, but the degree of thermal expansion and contraction of different objects is different. The two sides of the double gold sheet are conductors of different materials. Under changing temperatures, the double gold sheet bends due to different degrees of expansion and contraction. Touching the set contact or switch causes the set circuit (protection) to start working.
Note: KSD301 thermal cut-off switch series is SPST, plastic shell, 16A, 40A, 45A automatic reset form.
KSD302 thermal cut-off switch series is SPST, ceramic shell, 16A, 40A, 45A automatic reset form.
KSD303 thermal cut-off switch series is SPST, plastic shell, 16A, 40A, 45A manual reset form.
KSD304 thermal cut-off switch series is SPST, plastic shell, 16A, 40A, 45A double contact automatic reset form.
KSD305 thermal cut-off switch series is SPST, plastic shell, 16A, 40A, 45A double contact automatic reset form.
● The operating temperature performance is fixed, no adjustment is required, simple, reliable action, no arcing, long service life and less radio interference.
● Electrical parameters
AC250V 5A/10A/16A AC120V 7A
● Temperature working range: -25℃∽+240℃+1℃∽2℃
Can be produced according to user requirements
● Life span is more than 100,000 times
● Insulation value>100MΩ
● The product has high precision, good stability and good synchronization.
product structure
The KSD301 series product is a thermostat that uses a bimetallic sheet as the temperature sensing component. When the electrical appliance is working normally, the bimetallic piece is in a free state and the contacts are in a closed/open state. When the temperature reaches the operating temperature, the bimetallic sheet is heated and generates internal stress and moves quickly to open/close the contacts and cut off/connect the circuit. This plays a role in temperature control. When the appliance cools to the reset temperature, the contacts automatically close/open and return to normal working condition.
Widely used in: water dispensers, water heaters, sandwich toasters, dishwashers, dryers, disinfection cabinets, microwave ovens, electric coffee pots, electric cooking pots, refrigerators, air conditioners, glue laminators, office equipment, car seat heaters, etc. Electric heating appliances.
Product main uses
This thermostat is a small temperature controller with fixed operating temperature performance, no adjustment required, simple operation, reliable action, no arcing, long service life, and less radio interference. This thermostat is a small temperature control and overheat protection; such as sterilizing cupboards, electric water bottles, coffee pots, electronic tiles, hot water bottles, water dispensers, hair dryers, vacuum cleaners, electric heating stoves, microwave ovens, electric irons, dryers Clothing machines, motors and other electrical appliances.
(2) When the water dispenser is in heating state, R1 and R2 are connected in parallel.
(3) If the pointer of the ammeter is at the position shown in Figure 3 during heating and heat preservation, what are the currents flowing through R1 and R2 during heating?
(4) How many coulombs of charges pass through R1 and R2 after heating for 3 minutes?
Metal expansion thermal cut-out switch
According to the principle of thermal expansion and contraction of objects. Thermal expansion and contraction are common characteristics of objects, but the degree of thermal expansion and contraction of different objects is different. The two sides of the double gold sheet are conductors of different materials. Under changing temperatures, the double gold sheet bends due to different degrees of expansion and contraction. Touching the set contact or switch causes the set circuit (protection) to start working.
Note: KSD301 thermal cut-off switch series is SPST, plastic shell, 16A, 40A, 45A automatic reset form.
KSD302 thermal cut-off switch series is SPST, ceramic shell, 16A, 40A, 45A automatic reset form.
KSD303 thermal cut-off switch series is SPST, plastic shell, 16A, 40A, 45A manual reset form.
KSD304 thermal cut-off switch series is SPST, plastic shell, 16A, 40A, 45A double contact automatic reset form.
KSD305 thermal cut-off switch series is SPST, plastic shell, 16A, 40A, 45A double contact automatic reset form.
● The operating temperature performance is fixed, no adjustment is required, simple, reliable action, no arcing, long service life and less radio interference.
● Electrical parameters
AC250V 5A/10A/16A AC120V 7A
● Temperature working range: -25℃∽+240℃+1℃∽2℃
Can be produced according to user requirements
● Life span is more than 100,000 times
● Insulation value>100MΩ
● The product has high precision, good stability and good synchronization.
product structure
The KSD301 series product is a thermostat that uses a bimetallic sheet as the temperature sensing component. When the electrical appliance is working normally, the bimetallic piece is in a free state and the contacts are in a closed/open state. When the temperature reaches the operating temperature, the bimetallic sheet is heated and generates internal stress and moves quickly to open/close the contacts and cut off/connect the circuit. This plays a role in temperature control. When the appliance cools to the reset temperature, the contacts automatically close/open and return to normal working condition.
Widely used in: water dispensers, water heaters, sandwich toasters, dishwashers, dryers, disinfection cabinets, microwave ovens, electric coffee pots, electric cooking pots, refrigerators, air conditioners, glue laminators, office equipment, car seat heaters, etc. Electric heating appliances.
Product main uses
This thermostat is a small temperature controller with fixed operating temperature performance, no adjustment required, simple operation, reliable action, no arcing, long service life, and less radio interference. This thermostat is a small temperature control and overheat protection; such as sterilizing cupboards, electric water bottles, coffee pots, electronic tiles, hot water bottles, water dispensers, hair dryers, vacuum cleaners, electric heating stoves, microwave ovens, electric irons, dryers Clothing machines, motors and other electrical appliances.
