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26 Threads found on Transistor Protection Circuit
Can anyone suggest a replacement transistor? This 13.8v power supply (RadioShack) blew up on me many years ago and I have been dragging it around knowing someday I would repair it. Well, this weekend I finally got around to popping the cover on it. Blown fuse, replaced. Checked main electrolytic capacitor, suprized that
Hi, On a product with a PNP output (24V 200mA) what extra circuit components are required before interfacing the collector of the PNP transistor to the outside world in an industrial environment? I'm thinking in regards to EMC requirements (surge, burst, ESD), is there a 'tyipical' circuit? or a list of standard recommendations for robust (...)
I have 3miliohm , 4miliohm and 8miliohm with me, can you provide reference circuit. Simple method to measure current, referenced to the positive supply. A PNP transistor is operated in common base mode. The 4 m-ohm shunt is placed at the top of the load. obrazk
circuit is polarity protection of load connected on +12 point. Zener diode, resistors and transistor limits Vgs. circuit can be a part of battery supply.
Excellent analytical suggestions are given so far. When choosing a transistor , get one with single pulse power vs V ratings. Example of a 1W 60V NPN transistor. Notice 10ms @40V= 300mA max. . . You can extrapolate down to 10uS and obtain higher curren
OVP is to limit the output voltage. Use a P MOSFET switch to pass the input to output with no voltage drop. Then use a PNP transistor to turn off the switch. It can be regulated using a comparator with a 2.5V reference and divider on the output. the open collector driver can now drive the PNP base for a precision 40V series pass switch with a regu
In CMOS Process, I designed Large NMOS/PMOS switch transistor. To protect switches from large Ids current, I designed protection circuit and inserted it. It is supposed to operate when Ids current > 300mA , PMOS gate pull on(VDD) and NMOS gate pull down(GND). So Ids current doesnt flow any more. On the contrary to concerns, when (...)
Stall detection and motor shut-off is a standard feature of electric windows. Besides requiring a current measure feature (shunt, sensing transistor saturation voltage), controller circuit and suitable electronic switch, it depends on certain gear properties. There most be a sufficient margin between operation and breaking torque.
Please i need help : i have two separated electronic cricuit that communicate via uart, see attached, i didn't put directly the RX and TX of the two circuit i added transistor, i need help on how to protect my circuit from ESD or another
it will just be a digital output where the load(realy most probably) will be driven using a fet for transistor. the input supply will be from 24 to 60v but we have to implement a limit of .5A at 60V. at other voltages also shortcircuit protection must be there
hi am in a sensor related project and i did a short circuit protection by means of transistor and resistor.. its occupying more places in my circuit.. i need to know is there any dedicated ic is available for short circuit protection in market??
A current sense resistor will be mostly place in the source line of the transistor. It should be low resistance to reduce the voltage drop and power dissipation, but must be large enough to get a detectable voltage for the overcurrent detector. A simple short circuit protection can be formed by a current limiter, e.g. a single BJT (...)
Battery is cut off by deep discharge protection circuit. Now to reset the system I need to short circuit the battery and charger positive terminals, on receiving a initial pulse from charger. On this pulse I need to make a path between charger and battery. have a look at my circuit 55986 plz tell me how can i short ci
Hello, I'm using a regulator with the schematic posted in the image attached, powered from a 30V source with 20000uF filter caps that can probably deliver more than 20A for short periods. Unfortunately, the pass transistor blows instantly on short circuit. Q2 should limit the output current to 6-7A, but it seems it acts too slow, or the MOSF
Hi everyone I am trying to boost the current output of LM7805. A circuit is available here : On page 21 the circuit for Current boost with Short circuit protection is given. My question is, in the given circuit, the transistor used is of low gain type. I would like to use TIP127 instead
For me this circuit looks a little bit dodgy, as the forward voltage drop across the top BY398 diode may be to low to allow the transistor to be turned on .. To provide protection and not to interfere with the transistor, I’d use two diodes each way, and perhaps increase the value of the base resistor from 47ohm to, (...)
hi all looking for IC DP904C For Samsung CRT monitor , this ic work in switch mode circuit in samsung crt monitors , can i replace it by any other circuit or any solution imean this ic contain mosfet transistor with feedback and protection , can i transform it as regular crt monitors power supplies ?? please (...)
Hi gays: I have a question about LDO over current protection. the question is following: When the current of output transistor is to high, the protection transistor (PMOS) will pull up the gate of the power transistor to high voltage and close the power transistor. but the current flows (...)
Hi Shai, If in an regulator if the load ouput point has accidently been shorted to ground then a large amout of current will flow through the circuit and this can damage the pass transistor. Hence a short circuit protection can be used to detect this. Over current in a regulator can arise if the output load falls to a (...)
wisepie, I believe that he diode on the right should be an ordinary diode. In this application, the lower terminal of the relay coil would be connected to the +16V supply. When the transistor turns off, the inductance of the coil will try to maintain current flow thrugh the coil. with no protection circuit, the voltage on the (...)
hello attached is a simple h-bridge circuit from "pic microcontroller project book" can anyone describe whats the function of the 10k resistor to the 2 pair of transistors ? also in the original circuit hes putting a protection diode accross each transistor. isnt the tip120 already gut those ? thank (...)
hello my friend TDA4605-3.pdf SpecSheet : Control IC for Switched-Mode Power Supplies using MOS-transistor TDA 4605-3 Bipolar IC Features q Fold-back characteristics provides overload protection for q q q q q q q q external components Burst operation under secondary short-circuit condition implemented protection against (...)
The need for extra protection really depends on the process. Some of the processes I work with have very fragle NMOS transistors (drain silicide shorts to body) others are more robust. If the output transistor is large enough and is designed with the same rules as the ESD device then it could be OK. You really need to discuss this with the (...)
Does anyone have any idea about bulk driven transistor. Just hear today and only know it's for low voltage design. Anyone has example or reference for this? Thanks
circuit in Red block will maintain 1.235 V at the output by maintaining the common mode level of npn transitors in the reference generation block. If you notice the connection to the bases of the input are having a resistor drop.Hence they will maintain a level at the input and at the emitter of the output transistor. Mostly, this will work
Fuse.pdf needs a correction. The most right transistor must be PNP type (BC212) and base and emiter must be interchanged othervice circuit doesn't work.