82 Threads found on edaboard.com: Current Booster
Consider the following Common Collector & Darlington emitter follower circuits,
Let V(in) = 5V
Vcc(supply) = 10V
Emitter(load) resistance = 100 ohm
thus, V(out) should be 5V (following input)
Corresponding Load current will be 5/100 = 50 mA
Let V(in) = 5V
Vcc(supply) = 10V
Emitter(load) resistance = 33
Electronic Elementary Questions :: 03.02.2013 08:24 :: vinodquilon :: Replies: 16 :: Views: 667
All the circuits show Transistor for current boost with 78xx 3 pin regulator. Why don't they use mosfet instead of Transistor.
Hobby Circuits and Small Projects Problems :: 07.04.2004 07:43 :: palesha :: Replies: 1 :: Views: 1619
This diode protects regulator against discharge of the output capacitor to the output of the regulator in case when the input is shorted .. see picture below ..
Voltage regulators such as 78XX have internal current limit that limits the output current to 1A. If you need more current and still have a good voltage regulation you can use (...)
Analog Circuit Design :: 27.10.2005 21:24 :: IanP :: Replies: 10 :: Views: 3422
Again, as in current booster1, the vale of the resistor is wrong .. it should be somewhere between 3-10Ω ..
In this case current is limited by additional transistor, the 2N6049.
It happens when the voltage accross Rsc riches ≈0.65V and this tranistor starts to control Vbe of the power PNP transistor .. Iout≈0.65/Rsc
Analog Circuit Design :: 27.10.2005 21:35 :: IanP :: Replies: 4 :: Views: 834
Take a look at the attached picture .. It shows the way of boosting the output current of an opamp with NPN and PNP transistors .. Maybe you should try that concept ..
BTW> Why do you use LM311??? It is not an opamp - it is a comparator - so, in linear applications it is rather useless ..
Electronic Elementary Questions :: 30.08.2006 00:54 :: IanP :: Replies: 4 :: Views: 1677
A darlinton transistor would have alot of current on the output
How can i make a tube have alot of current on the output instead of alot of voltage?
Mostly tubes preamps boost the voltage from input to output
A transisstor boosts the current from input and out
But how can i make a tube circuit preamp boost alot of (...)
Electronic Elementary Questions :: 21.02.2008 21:02 :: walters :: Replies: 1 :: Views: 661
Hello , I'm in computer engineering department . i design some project with my own idea . i use LM741 op-amp to output amplified voltage that i needed but output current is less than < 20 MA and i want to reach 1 A at least. so anyone knows how to reach this current value without changing this voltage value , like current amplifier or (...)
Analog Circuit Design :: 10.03.2008 16:33 :: bekerpico :: Replies: 1 :: Views: 659
your question does not make alot of sense.
You cannot boost both the voltage and current.
If your 6V supply is capable of delivering 25AMPS - that is 150 Watts
Power = Volts X current
if you boost the said voltage to 12V, assuming 100% efficiency! the current available will only be 12.5AMPS.
In practice it is (...)
Analog Circuit Design :: 28.02.2010 20:07 :: xaccto :: Replies: 16 :: Views: 3096
I have a relatively high impedance energy source of about 10~12V,4mA which amounts to about 40mW. Can anyone suggest me a high efficiency power supply circuit ( preferably greater than 80%) which can boost the output current to 10mA at the expense of the output voltage reducing to a minimum of 3V preferably regulated.
Input power = 7
Analog Circuit Design :: 08.11.2010 09:09 :: islurpundalik :: Replies: 0 :: Views: 498
I have used the LM2700 to boost a 5v supply to 12v (currently using a laboratory power supply). The behavior is fine but when the load needs a surge of current (1A), the input and output voltage drops significantly. Will like to ask if there's any workaround to give a short current boost when needed.
I remember the buck(step down) (...)
Analog Circuit Design :: 31.07.2011 09:48 :: alpha86 :: Replies: 5 :: Views: 782
For an exact answer, you need to consult the transistor datasheet and find out the actual Vbe values. In a rough estimation, the current will double according to ohms law. There's no circuit means to regulate the current.
May be you are intending something different, but you didn't yet tell what you want to achieve.
Electronic Elementary Questions :: 23.07.2012 14:36 :: FvM :: Replies: 7 :: Views: 313
Volt regulators such as the LM708, and
LM317 series (and others) sometimes need
to provide a little bit more current then they
actually can handle. If that is the case, this
little circuit can help out. A power transistor
such as the 2N3772 or similar can be used.
The power transistor is used to boost the
extra needed current above the maxim
Hobby Circuits and Small Projects Problems :: 02.08.2013 01:55 :: nhawan429 :: Replies: 0 :: Views: 10
You could connect pin 3 (emitter) to GND and connect pin 4 (collector) to 5 V through the LED and a current limiting resistor.
If you need more current you should read this application note:
Look at Figure 3
Hobby Circuits and Small Projects Problems :: 25.05.2003 12:31 :: ME :: Replies: 3 :: Views: 1532
This is not a booster, but just a set of decoupling caps.
The internal LCD controlling voltages are probably made with a resistor divider network on-chip, and for peak currents this may not be stable enough. A capacitor on-chip takes too much precious space. That's why they want you to put a storage capacitor externally: to supply brief pulses of
Microcontrollers :: 29.12.2004 06:27 :: vomit :: Replies: 10 :: Views: 2513
You can try this method:
connect a small 220/12 (or less) transformer between each phase and Neutral (I asume you have access to N or E, in isolated circuits the primary should be rated for 400V and connected betwee phases). If you want to monitor each phase separately you will need 3 circuits with OR function at the final stage.
Rectify the volt
Electronic Elementary Questions :: 01.02.2005 08:37 :: IanP :: Replies: 2 :: Views: 1536
Usually we consider a lower current for gain-booster. That's because we always like to have less power consumption. On the other hand, gain of the gain-booster is usually larger for smaller current values.
As you know, the gain-booster path introduces a zero (because we have two paths, a slow path and (...)
Analog Circuit Design :: 21.07.2005 07:11 :: ezt :: Replies: 11 :: Views: 5113
My booster DC/DC is an Inductor-based step up DC/DC converter. It can work
from 0.9V start up voltage, output a 3.3V voltage and driver a 3.3K load.
When the Vin from 0V to 2.0V, the current has a max current 500mA, this is to say it need a power MOS that can source 500mA at least. But now it can't do that.
How to adapt the power MOS?
Analog Circuit Design :: 04.09.2005 20:45 :: horzonbluz :: Replies: 9 :: Views: 1035
The Tip30c and Tip152 form a current booster, in order to permit that the regulator can deliver more than 0.700mA.
Analog Circuit Design :: 14.09.2005 10:03 :: bomba :: Replies: 6 :: Views: 959
The regulator is working fine, without the current booster. The problem is, when I connect the current booster the BUT56A became short-circuited between Collector to emitter. Why you say that the BUT56A is not for this kind of application.
I need to replace the tip30c for another transistor that can support more than (...)
Analog Circuit Design :: 18.09.2005 10:56 :: bomba :: Replies: 7 :: Views: 1250
have u used any isolation ckt between controller and motor,and used any current booster ckt? i too met with the same prob when i designed a robo using 89c51, i think if the motor runs one step fwd and one step bwd means the wire connection will be wrong, otherwise u try to increase the delay of the prog, or use an any current (...)
Electronic Elementary Questions :: 27.10.2005 13:30 :: brahma :: Replies: 6 :: Views: 890
I need a circuit which can boost voltage and current from a low voltage and maintain it without fluctuations..could someone please help :)
Electronic Elementary Questions :: 09.01.2006 10:00 :: kad :: Replies: 4 :: Views: 578
a 400 ohms relay can not be driven by water resistance.waterresistance is above several kilo ohms. so you need to make a circuit like current booster, level sensor or buy a ready-made a controller called "sivi seviye rolesi"....
Analog Circuit Design :: 12.02.2006 06:19 :: nec3 :: Replies: 6 :: Views: 2118
try to lower mosfet input resistance by resistor connected to gate source . Or better to use low output impedance buffer (current booster) before mosfet .
But what is the spike parameters - rise time, amplitute and others and type of mosfet you use?
Analog Circuit Design :: 24.02.2006 05:17 :: artem :: Replies: 6 :: Views: 2079
i think that kwkam is right , the upper side of r17 has to be connected to ground instead of +15 V.
Q1 - Q4 make together current booster and i dont see incorrect polarity of BJTs but what i see is poorly designed scheme or there is something hidden) :
- Why to boost current if Q1 Q4 limited by 10 kOm resistors ?
- Why the positive (...)
Analog Circuit Design :: 15.04.2006 14:08 :: artem :: Replies: 6 :: Views: 743
we all know that when the emitter of the 1st transistor is connected to the base of the 2nd, the 2 transistors together acts as a current booster(darlington). will it also be correct if the collector of the 1st transistor is connected to the base of the 2nd? is there anything wrong?
thank you in advance,
Electronic Elementary Questions :: 09.11.2006 09:37 :: amriths04 :: Replies: 5 :: Views: 1417
External booster is required to step up voltage from 3.3V to 18V to drive OLED.
The max. loading current for OLED is around 20mA.
Is there any cheap alternative method to step up voltage from 3.3V to 18V instead of using booster ?
Professional Hardware and Electronics Design :: 06.06.2007 23:37 :: ricky_wcy :: Replies: 1 :: Views: 1365
Is their any booster IC which gives 5V and 12V output from single Li-Ion cell
with current of 250mA from each ouput
Analog Circuit Design :: 28.04.2008 09:00 :: saurav_sdpl :: Replies: 0 :: Views: 474
I have been thinking for a while to come up with a clever solution.
I have a mini current source that produces around 0.5V. The output is in the order of ?A. I would like to boost the voltage to 1.6V.
Can this be easily done?
Analog Circuit Design :: 06.08.2008 03:38 :: MathGeek :: Replies: 4 :: Views: 1216
It is because ur 7segment draws more current.
Try using another 7805 in parallel
or a current booster.
BTW do you have a heat sink for 7805?
Microcontrollers :: 04.02.2009 02:13 :: nandhu015 :: Replies: 5 :: Views: 808
I think what you need is a comparator driving a relay so the cell switches off at a certain, predetermined light level.
Use the photoresistor and a fixed resistor to make a potential divider and feed it to one side of a comparator. Use a potentiometer on the other comparator input so set the light level at which it will change state. The using a
Electronic Elementary Questions :: 23.09.2009 15:26 :: betwixt :: Replies: 3 :: Views: 984
My RTC is a DS1337
In this case, you don't need a driver. The DS1337 nINT output is open drain and can drive 5V directly without a driver. If the
current capabilty (3 mA) isn't sufficient, you can connect a pnp BJT in common collector configuration as a current booster,
assumed 0.6V voltage drop above ground is allowed for the c
Analog IC Design and Layout :: 02.03.2010 14:28 :: FvM :: Replies: 6 :: Views: 1463
please i need a circuit diagram that can amplify 220v ac 3W to about 1kW
At what voltage level do you need 3kW...? If you want 1kW from a 220v, 3W source at the same voltage level, it will be against the law of conservation of energy!!
P = VI where P is the power, V is the voltage and I is the current.
For your scenari
Electronic Elementary Questions :: 12.07.2010 20:23 :: deepuj :: Replies: 1 :: Views: 989
the attached is a booster amp used a gain boosted ota, from one berkeley student's project report.
I don't understand why he used cascoded tail current source with one transistor controlled by biasing network and another by cmfb. Any particular advantage of this topology compared to normal cmfb tail current source (two parallel (...)
Analog IC Design and Layout :: 30.06.2010 18:01 :: jszair :: Replies: 0 :: Views: 458
i think what you have here is one ic regulator with one transistor current booster circuit. However, the value of your ic is not given. I suggest you deside on what is should be, like say, LM317 and use 'Isis Proteus' to simulate your scematics.
Software Problems, Hints and Reviews :: 04.07.2010 07:48 :: Fidelis Anyanti :: Replies: 5 :: Views: 924
I just registered.
I am not specifically electronic trained, but I have some hobbyist notions.
I am trying to create an adjustable current regulated power supply.
Input: 3-4V DC (more specifically, a single LiIon cell, 18650)
Output: 3-7V DC @ a maximum of 1.5~2 Amperes.
constant current, Adjustable via potentiometer o
Power Electronics :: 01.05.2011 13:59 :: anselm :: Replies: 1 :: Views: 444
A brief overview can be found here: Piezoelectricity - Wikipedia, the free encyclopedia
To give a short explanation of my own, a piezoelectric element can be seen as ceramic capacitor with a built-in series voltage source. Applying a force creates a proportional voltage. It appears as a current puls
Power Electronics :: 06.06.2011 15:48 :: FvM :: Replies: 6 :: Views: 763
For a resistive load (which is what you are trying to emulate) if the mains goes up briefly then the current to that load goes up briefly too. so it is a good thing if a PFC booster emulates this. It also adds to the stability of the mains network, if the input current went down instantaneously (constant power load) as the mains voltage (...)
Power Electronics :: 05.08.2011 18:56 :: Orson Cart :: Replies: 2 :: Views: 684
I wanted to make a voltage booster in order to power up some projects that need more than 9V supply with only 9V battery.
I searched in local market for chips that make voltage boost but I didn't find ,I decided to build it my self.I did make a fly-back sps but the output current was very low.I decided to make a boost sps in order to d
Analog Circuit Design :: 23.09.2011 18:43 :: quaternion :: Replies: 11 :: Views: 750
3.7V output... Are you by any chance looking for a way to light a bright white LED, using a single cell?
There's an interesting circuit which has become popular under the name 'Joule Thief.' It will take juice from a weak battery and convert it to sufficient voltage/current to light a bright white led.
It involves wrapping a tiny ferrite bead
Analog Circuit Design :: 29.12.2011 03:12 :: BradtheRad :: Replies: 7 :: Views: 960
why does the voltage shoot up to about 20V and then slowly decay back to 11V?
At startup, the capacitor is like a short circuit.
This allows surge current to go through most all the components... although it takes a moment to build due to the coil reactance.
Once current has built up, the coil keeps it flowing, causing the tempo
Analog Circuit Design :: 12.08.2012 22:29 :: BradtheRad :: Replies: 6 :: Views: 354
You'll need to make sure the driver operates at or less than 99 percent duty cycle. It must sometimes go to the Off state. It must not go into permanent On-state in an effort to make output rise to your desired level.
Duty cycle will be different for a given combination of load and desired voltage on it.
After any change in duty cycle, you'll nee
Microcontrollers :: 14.10.2012 05:18 :: BradtheRad :: Replies: 3 :: Views: 265
Assume A is a standard operational amplifier with e.g. 20 mA maximum output current and compensation current Is is is as high as 200 mA. Then you need a current booster stage like the complementary emitter follower shown in the schematic.
Electronic Elementary Questions :: 26.11.2012 13:31 :: FvM :: Replies: 5 :: Views: 339
In practice I have oscillation and I think that the reason for that could be multi-poles system.
In practice, small signal analysis doesn't describe the system behaviour completely. The most severe point is the class B current boost stage where both MOSFETs are off for the calculated bias point. In addition MOSFET and IGBT capacita
Analog Circuit Design :: 03.05.2013 11:31 :: FvM :: Replies: 8 :: Views: 295
You are asking for up to 20X increase. This means the duty cycle needs to be very high, on the order of 97 or 98% (according to my simulation). During that part of the cycle, current goes through the switching device (mosfet).
Hence only 2 or 3 percent of each cycle goes to the output stage.
It is normal operation in a boost converter, if you wi
Analog Circuit Design :: 19.05.2013 16:51 :: BradtheRad :: Replies: 6 :: Views: 417
There are some very good LDO regs out there that draw little or no current, check out AAT!
Schotky diode all the unused outputs from the pc into the LDO and turn them on.
PC Programming and Interfacing :: 16.09.2002 17:59 :: btbass :: Replies: 14 :: Views: 3401
Hi, hopefully this is the right section for this post! Anyway...
I have linked together all the VCR's in my house (along with the cable box) to allow them to be viewed on any TV in any room. However, the house is fairly big and the signal goes through at least 80m of coax, possibly more, before getting to the main distribution amplifier which sp
Other Design :: 21.12.2004 09:47 :: seven_segment :: Replies: 3 :: Views: 1174
There are several ways of generating 48V from 9 or 18V. Very simple one would be voltage multiplier (X3, X4 ..) but if you need more current the LM3578 with or without external transistor can do the job.
(voltage booster: )
Hobby Circuits and Small Projects Problems :: 17.03.2005 05:29 :: IanP :: Replies: 2 :: Views: 2180
First of all, there is an error on the drawing: -V is obviously +V ..
There are 4 identical blocks in this circuit, so lets concentrate on block 1 build around transistors T3 and T8 (to small print to read)..
When SW1 is closed current flows through D3, R23 and D11 to the Base of T8 putting T8 into saturation. Voltage on its collector goes low
Electronic Elementary Questions :: 05.10.2005 03:40 :: IanP :: Replies: 4 :: Views: 831
Transformer is a power converter, not an amplifier ..
If voltage is doubled in the secondary, current is halved in the secondary. Conversely, if voltage is halved in the secondary, current is doubled in the secondary. In this manner, all the power delivered to the primary by the source is also delivered to the load by the secondary minus w
Electronic Elementary Questions :: 08.03.2006 07:29 :: IanP :: Replies: 7 :: Views: 477
That's an unusuall circuit. It looks like a flying-capacitor boost regulator.
I'm not convinced it actually works just from the circuit diagram.
When Q673 is on it allows C678 to charge up to about 4.3V from the 5V input through D670.
When Q673 is off C678 and R678 are in series with
the 5V supply.
After the drop across D671 and D672 I can
Analog Circuit Design :: 24.04.2006 22:39 :: throwaway18 :: Replies: 3 :: Views: 996