Showing posts with label low. Show all posts
Showing posts with label low. Show all posts

Friday, October 24, 2014

Low drop Regulator with Indicator Circuit Diagram

Even today much logic is still powered from 5 volts and it then seems obvious to power the circuit using a standard regulator from a rectangular 9-V battery. A disadvantage of this approach is that the capacity of a 9-V battery is rather low and the price is rather high. Even the NiMH revolution, which has resulted in considerably higher capacities of (pen-light) batteries, seems to have escaped the 9-V battery generation. It would be cheaper if 5 volts could be derived from 6 volts, for example. That would be 4 ‘normal’ cells or 5 NiMH- cells. Also the ‘old fashioned’ sealed lead- acid battery would be appropriate, or two lithium cells.
 
Circuit diagram : 
Low-drop Regulator with Indicator-Circuit-Diagram
Low-drop Regulator with Indicator Circuit Diagram
 
Using an LP2951, such a power supply is easily realised. The LP2951 is an ever- green from National Semiconductor, which you will have encountered in numerous  Elektor Electronics designs already. This IC can deliver a maximum current of 100 mA at an input voltage of greater than 5.4 V. In addition to this particular version, there are also versions available for 3.3 and 3 V output, as well as an adjustable version.  In this design we have added a battery indicator, which also protects the battery from too deep a discharge. As soon as the IC has a problem with too low an input voltage, the ERROR output will go low and the regulator is turned off via IC2d, until a manual restart is provided with the RESET pushbutton.
 
The battery voltage is divided with a few resistors and compared with the reference voltage (1.23 V) of the regulator IC. To adapt the indicator for different voltages you only need to change the 100-k resistor. The comparator is an LP339. This is an energy-friendly version of the LM339. The LP339 consumes only 60 µA and can sink 30 mA at its output. You can also use the LM339, if you happen to have one around, but the current consumption in that case is 14 times higher (which, for that matter, is still less than 1 mA).
 
Finally, the LP2951 in the idle state, consumes about 100 µA and depend- ing on the output current to be deliv- ered, a little more. 



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Thursday, December 26, 2013

High pass and low pass filters

Subsonic and ultrasonic filters can be combined into a single circuit for more stable and orderly bandwith. This good and qualified for only two frequencies with the rotation of widely separate. Circuit schematic above shows the rotation of the scond-order or high-pass Butterworth filter in combination with secon-order low-pass filter.
op amp bass
Part List :
R1___1K
R2___1K
R3___12K
R4___24K
C1___4n4
C2___2n2
C3___470nF
C4___470nF
IC___IC op-amp

For the capacitor , use the ceramic capacitors .
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Sunday, December 15, 2013

Low impedance microphone amplifier


The circuit is a microphone amplifier used for handle with low impedance (~200 ohm) microphones. It hope against hope job with stabilized voltages sandwiched between 6-30VDC. If you dont build the impedance adapter part with T1, you obtain a micamp for upper impedance microphones. within this indictment, you ought to honestly bond the suggest to C7.

Low impedance microphone amplifier
Add captionLow impedance microphone amplifier
R1=15k
R2= 150k
R3= 2k2
R4= 820
R6= 10k
R7= 10k
P1= 1M
C1= 3k9
C2= 100u
C3= 22u
C4= 4u7
C5= 470u
C6= 10u
C7= 100n
C8= 47u UNIPOLAR
D1= 1N4148
U1= TL081
CN1= SIL6
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Wednesday, December 4, 2013

Tone control low noise circuit

Tone control or pre-amplifier is an amplifier circuit supporters. Sometimes some of us do not know where a good amplifier, a raft alone and the results are not much different or even the same. Therefore we must know the character of the advantages and disadvantages of each amplifier equipment.

Tone control low noise here does not mean without noise, but noise compared with the lowest tone control on the market, for example Ronica transistor 4, TL-084, TC-2 LM833 etc.

CSE | Circuit Schematic Electronics

Jump to explanation of each component ...

Potensio 1 serves to regulate the intensity / level of the incoming signal is assisted potensio 2 as balance / counterbalance. Potensio 2 is still installed and is usually an optional component. 1-2uF/250V capacitor R1 is actually a brand name, but I prefer to replace it with a 1K resistor / 5% normal for reasons to avoid hum and interference sensitive. R2 R3 while minimizing interruption to adjust the impedance OP-amp 1. R4 and R5 serves to increase the gain of 1.3 times. Pre amplifiers typically use a strengthening standards by 2 times, but by most of us think it has a noise. So I chose the value of 1.3 times, but the most minimal noise signal from the volume is enough to make the lamp light peak.

For low noise ... Cause of noise in op amp 1, apex audio even eliminate this stage. Can This step is also used as a buffer (jumper R5), the strengthening of a time. Lower values ​​increase the value of R5 or R4 with consequent gains to be less, but remains at a value above 1 times due to input non-inverting path to take, so that the signal and noise can be reduced. R4 can also be replaced with a 10K trimpot and middle leg into the bass range adjuster (bass resonance).

C1 and C6 as a filter to reduce the treble / high frequency of excessive or often called oscillation prevention. R6 is actually an optional component of the impedance a little help customize the system. Ideally the same as the R8 R7 to facilitate give the sign of the gain on potensio panel tone control. C2 and C3 form a series circuit treble filter (high pass filter), its value is greater then the sound that passed the mid. C4 and C5 assisted by R9 and R10 form the low pass filter (filter bass), the greater the value of C is a bass sound that will be missed the soft / low (maximum of 47nF), the smaller the value of c is the bass signal that is passed will further dip (dig-dig, c4 = c5 = 22nF). This value is suitable for 27-33nF, 47nF instead (depending on taste). Pot 3 & 4 pot set treble and bass levels, the greater the greater the value of this potensio gains (bass & treble including potensio volume). R11 adjusts the output impedance, while the R12 and the red LED indicator that shows if the amplifier Peak has been given a full signal.

15V maximum supply. TL074 IC can, but in designing the PCB, IC can be replaced with 2x TL072/NE5532/4558.
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