​how to detect a varactor?

how to detect a varactor?

Because the positive resistance of the varactor diode is larger,the multimeter is placed in the RX 10k2 block,the red form is connected to the positive pole,the black pen is connected to the negative pole,and the resistance value between the two pins should be infinite.If it is found that the pointer of the multimeter has a slight swing or a resistance value to zero on the measurement,it means that the varactor diode has leakage fault or has been damaged. Reverse the form,that is,the red pen is connected to the negative pole and the black pen is connected to the positive pole.The measured resistance should be around hundreds of thousands of euros.For the vanishing capacity of the varactor or the open-circuit fault inside,the multimeter can not be detected,and the replacement method is applied to judge. 

What is a magneto diode? 

Magneto -sensitive diode is a new type of magnetoelectric conversion device.The utility model has the advantages of high detection sensitivity,small size,fast response,no contact,large output power and good linearity.Should be widely used in magnetic detection,contactless switch,displacement measurement,speed measurement and various automatic equipment.

Characteristics and principles of a magneto sensitive diode The shape and symbol of the magnetic sensitive diode are shown in Figure.The text symbols are represented by VDC. The longer pin is the positive electrode ( P + area ),and the shorter pin is the negative electrode ( N + region ).The convex surface is the magnetic sensitive surface.The internal structure of the magneto diode is different from that of the ordinary diode. When the external magnetic field is absent,the device star is stable.If a positive magnetic field is added to the outside,the external resistance increases,the current decreases,and the pressure drop increases:on the other hand,the external magnetic field is added,and the external resistance decreases,the current increases,and the pressure drop decreases.

parameters of magnetic diode

The main parameters of the magneto diode are: rated working voltage Vo, working current 1o, frequency of use fo.for example: domestic 2AGM 1A tube,Vo= 12V,2mA

how to detect a magnetic diode?

Figure shows the magnetic diode detection circuit.The ammeter and voltmeter show the static current and voltage respectively.A magnet is swinging next to the magneto diode,and the ammeter and voltmeter should swing,indicating that the magneto diode is good (this method is also a sensitivity test).If it does not swing,it shows that the pipe is bad.