For AC circuits other protection circuits are used. For DC circuits a rectifier diode is wired across the coil in reverse to arrest the high voltage.
2N3055 TRANSISTOR MAX BASE CURRENT DRIVER
When current in an inductor is stopped, it develops a very high voltage that could destroy the driver if the voltage isn't arrested. It has a high gate to source capacitance that needs to be charged with a high current for fast switching.įor SCRs and TRIACs, look them up in our Articles section above, or in. The Mosfet's gate drive isn't simple if you want it to switch on and off quickly. They perform even better with more gate voltage. Some Mosfets are designed to be driven by 5V logic. Curves in the datasheet show how typical devices perform poorly with gate voltages less than 10V. The Rds drain-source resistance is spec'd with a gate voltage of 10V. If it is very cold then the gate voltage must be at least 6V to turn it on a tiny amount. It is a current-controlled device where a small amount of current at the base terminal is mainly used to control a huge current at the remaining two terminals like emitter & collector. The voltage is a range from 2V to 4V because each one is a little different. The 2n3055 is an NPN transistor functions like a normal transistor that includes three terminals such as emitter, base, and collector. Its gate threshold voltage where it will conduct a tiny amount of current (1mA) is from 2V to 4V. tances in the base and collector regions may become significant, affecting the transistor terminal characteristics. If you want to use an IRF640 Mosfet then look at its datasheet:Īt room temperature if you apply 1V to the gate then it will do nothing. The maximum collector-to-emitter voltage for the 2N3055, like other transistors, depends on the resistance path the external circuit provides between the base and emitter of the transistor with 100 ohms a 70 volt breakdown rating, V CER, and the Collector-Emitter Sustaining voltage, V CEO(sus), is given by ON Semiconductor. The Mosfet dissipates far less power ( less heat wasted) than a 2N3055 and its gate doesn't dissipate anything since it is a very high resistance. The hFE is rated with a 4V collector voltage and much more base current is needed in order for it to saturate well with a lower saturation voltage.Ī modern power Mosfet is much more efficient if you have 10V to drive its gate.
The collector will dissipate 30W of heat and the base-emitter will dissipate probably about 6.6W of heat. For a collector current of 10A, a base current of 3.3A is required for the weakest one to saturate to only 3V. The circuit works but I’m not sure that is perfectly ok. In the picture you can see that I’m using a 2n2222 that controls a TIP3055 (or a 2N3055).
2N3055 TRANSISTOR MAX BASE CURRENT FULL
I need to control the speed of a dc motor (0.5 A no load, to 10 A full load). Its max Vbe is 1.5V with a fairly low base current of less than 400mA and is higher (but not rated) for higher base currents.Īs you can see by the decreasing ratio of collector current to base current, as the collector current is higher in order for it to saturate as well as it can then it needs a massive base current. Control DC motor with transistor 2N3055, pwm from Arduino. A transistor also has a maximum amount of base-emitter voltage that must be provided by the base current source. Transistors need a minimum amount of base current to turn on, depending on the amount of collector current and amount of saturation voltage that you desire.