Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [current-limiting]

Current limiting is the practice in electrical or electronic circuits of imposing an upper limit on the current that may be delivered to a load with the purpose of protecting the circuit generating or transmitting the current from harmful effects due to a short-circuit or similar problem in the load.

Current limiting is the practice in electrical or electronic circuits of imposing an upper limit on the current that may be delivered to a load with the purpose of protecting the circuit generating or transmitting the current from harmful effects due to a short-circuit or similar problem in the load.

697 questions
4
votes
5 answers

Can someone explain the protection resistor in this current limiter?

I am looking at this current limiting circuit on Wikipedia, which says that The optional component R2 protects Q2 in the event of a short-circuited load. Can someone explain why Q2 needs protection in this condition? My understanding is that…
sebf
  • 553
  • 1
  • 6
  • 15
3
votes
1 answer

Choosing wattage for current limiting filament bulb

I am building a fully featured breadboard/prototyping box for audio circuits and would like to include a current limiting light bulb that will be in circuit when I apply power to the box and then I can switch it out if everything looks OK. I am…
disorder
  • 161
  • 2
  • 13
2
votes
2 answers

Risk in limiting current with light bulbs in parallel

I'd like to make a current limiting device on the cheap using some light bulbs. I've seen somewhere the idea of connecting light bulbs in series to limit the current. For example, I'd wire a 250w light bulb in series to limit the current used by the…
Loïc Faure-Lacroix
  • 349
  • 10
  • 23
1
vote
0 answers

current limiter with MOSFET

I got a circuit from a current limiter for 12V by using a P-MOS, this is apply at the output from a DC/DC converter, I have to limit the current for 5 different voltages. I want to understand how the circuit with the PNP are working and how I can…
Taru WRC
  • 11
  • 1
1
vote
5 answers

Is there a way to reduce current, other than PWM, without creating heat?

I'm trying to reuse/salvage an old 12V DC car radiator fan for a non-car related project, and have found that it has a high load (actually seems to be somewhere around 200W, as it's a powerful fan). I want to reduce the speed of the fan because I…
Nick Bolton
  • 2,083
  • 10
  • 36
1
vote
0 answers

low voltage current limiter

I have master device / board that is connecting to PC USB. On board is LDO (1A) with 5V USB input and 1.8V - 3.6V output. LDO powers master board but also slave boards (different boards designed by others, not me) that can be connected /…
josip
  • 101
  • 5
1
vote
2 answers

Current limiter with low voltage drop out

I am looking for way to limit the output current from a LDO (Vout = 5V) to max. 150mA. I found only this circuit but the problem with this circuit is the voltage drop Vbe of the transistor Q1 and voltage drop across Rsense are too big. Using a…
zud
  • 1,846
  • 6
  • 26
  • 43
1
vote
2 answers

LM350 current limiter

Why is the following circuit an adjustable current limiter? It looks like a adjustable current source to me. EDIT: I know the difference between current limiters and current sources. Lets analyze the circuit the clear up some…
Henk
  • 509
  • 2
  • 7
  • 12
0
votes
1 answer

Very cheap current limiter circuit

I need to design the cheapest possible current limiter. My system consists of: half-bridge driver - NCP5901BDR2G - with the enable pin (high state of the pin is enable, low state disable outputs), pairs of mosfets connected to the 8V line - half…
piotr
  • 332
  • 1
  • 6
0
votes
2 answers

Limit voltage in a car

Is there a simple way or is it even possible to limit voltage in the circuit of a car? Let me explain my problem, I’m experiencing voltage drop while cranking that is too low for the ECU to open the fuel injectors. I want to install a second battery…
Hayden Black
  • 1
0
votes
0 answers

Efficiently use a power supply with limited current (24 V, 6 mA, Mbus)

I'm trying to make a slave device that gets power from a bus - per spec, I am allowed to draw 24 V, 6 mA maximum (the bus goes to 36 V sometimes, and under certain circumstances I'd be allowed to draw more power - but not always, but we can assume…
Overrice
  • 121
  • 6
0
votes
2 answers

Fixed current limit

I am going through The Art of Electronics, 3rd Edition improved. In chapter 12.4.4, Protecting power switches, Figure 12.45 shows current limiting the high side switch; B: fixed current limit: simulate this circuit – Schematic created using…
Cahir
  • 61
  • 4
0
votes
2 answers

Best way to limit maximum DC current?

I am making a device that provides a maximum of 35 mA @12V DC for a skin care system through a wire. I have a 12 V DC supply capable of 120 watts. What is the safest and simplest way to limit the current through what is essentially a short across…
Oscar
  • 91
  • 1
  • 6
0
votes
2 answers

Why does current flow through 1M resistor in this case?

I asked a question about protecting a circuit from current spikes from a piezo electric device: Protecting circuit from piezoelectric disc voltage spike. Someone graciously provided me with a solution in the image below. I have a follow-on…
mj_
  • 345
  • 3
  • 10
0
votes
1 answer

Limiting current without dropping volts

Can I limit 12v 25A current to 18A without dropping that 12v?
Ammar Fares
  • 1
1
2