Principle parameters and Application guide of the

The principle, parameters and Application guide of self restoring fuse

principle introduction

wh self resetting overcurrent protector (self restoring fuse) is made of high-tech polymer resin and nano conductive grains through special processing. Under normal circumstances, nano conductive crystals form a chain conductive path with the resin base chain connection, and the wh protector works normally; When the circuit is short circuited or overloaded, the large current flowing through the wh protector increases its collecting temperature. When the Curie temperature is reached, its density of state decreases rapidly, the phase transition increases, the internal conductive link changes or breaks in an avalanche state, the wh protector moves to a high resistance state in a step manner, and the current is quickly clamped off, so as to quickly and accurately limit and protect the circuit. Its small current keeps the wh protector in a protective state, After power failure and troubleshooting, its set temperature decreases, the density of States increases, the phase transition recovers, the nanocrystal is restored to a chain like conductive path, and the wh protector returns to its normal state without manual replacement

application scope

communication equipment: SPC exchange, user terminal equipment, general wiring security unit, etc

automotive electronics: automotive wiring harness, automotive anti-theft device, automotive micro motor, automotive electronic products, etc

electrical equipment: satellite receiver, security equipment, loudspeaker, industrial automatic control, etc

electronic industry: power supply, ballast, micro motor, fire alarm, instruments and meters, etc

product advantages

easy installation: wh self resetting overcurrent protector has no polarity, and can be connected in series with the circuit that needs protection. It is not only widely used, but also safe and reliable

reuse: after cutting off the power supply and troubleshooting, it will automatically return to the normal state without manual replacement and can be reused

no Reconnection: under fault conditions, the fault circuit will not be reconnected (other protection circuits, bimetallic sheets, etc. will be repeatedly connected to expand the fault range)

improve quality: it can improve the quality of customers' products, greatly reduce the natural damage rate of finished products, and can be 4.5% Polyphenylene oxide: with high heat resistance and chemical corrosion resistance, it can greatly prolong the service life of products

add highlights: because of the addition of high-tech elements, it can add new flash points to customers' products, so that vulnerable circuits are no longer fragile

reduce cost: reduce the number of components, PCB area and damage during operation compared with other protection circuits. Reduce the defect rate and after-sales service cost

efficiency improvement: it can improve the design efficiency of engineers and the accuracy and reliability of protection

improve reputation: it can improve the reputation of customer companies and the market competitiveness of products

installation method

whptc self resetting fuse has no polarity, small impedance and convenient installation. It can be connected in series with the circuit of the protected appliance, and the power supply can be DC or AC

symbol description

symbol description

maximum working current of IH whptc element at 25 ℃ ambient temperature

it minimum current of whptc element starting protection at 25 ℃ ambient temperature

IMAX whptc element can withstand maximum current

consumption efficiency of PDMAX whptc element under working state

maximum working voltage of Vmax whptc element

maximum voltage of vmaxi whptc element under blocking state

rmax wh The initial minimum resistance value of PTC components before operation

rmaxi whthe initial maximum resistance value of PTC components before the end of operation

selection guide

· list the maximum normal working current (I) and maximum working voltage (V) on the equipment circuit

· list the normal value and range of the working ambient temperature, and calculate the normal current IH according to the reduction rate (see the reduction rate table of ambient temperature and current values for details)

· according to the values of I and V, The product category and installation method choose a "Wanhe" brand self resetting overcurrent protector series. (refer to the specification tables)

· the I value of the selected "Wanhe" brand self resetting overcurrent protector must be less than or equal to IH

· if the user has special requirements for my company's products when I enter the disassembly workshop, please contact our company, and we will carry out special research and development by gently placing the pendulum on the base and lifting it according to your requirements, without any additional cost

table of reduction ratio of ambient temperature and current value

wh series -20 ℃ 0 ℃ 25 ℃ 30 ℃ 40 ℃ 50 ℃ 60 ℃ 70 ℃ 85 ℃ wh 600 138% 119% 100% 92% 83% 73% 64% 55% 42% wh 250 132% 117% 100% 91% 85% 77% 68% 61% 48% wh 130136% 119% 100% 92% 81% 72% 63% 54% 40% wh 60 136% 119% 100% if the traditional concrete based structure is adopted 90% 81% 72% 63% 54% 40% wh 30 130% 115% 100% 91% 83% 77%.68% 61% 52% wh 1 6 132% 120% 100% 96% 88% 80% 71% 61% 47% wh 6 130% 115% 100% 91% 83% 77% 68% 61% 52%

model description

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