Wiring Material: low

Monday, January 26, 2015

Low Cost Guitar Amplifier

The aim of this design was to reproduce a Combo amplifier of the type very common in the sixties and the seventies of the past century. It is well suited as a guitar amplifier but it will do a good job with any kind of electronic musical instrument or microphone. 5W power output was a common feature of these widespread devices due to the general adoption of a class A single-tube output stage (see the Vox AC-4 model). Furthermore, nowadays we can do without the old-fashioned Vib-Trem feature frequently included in those designs.

The present circuit can deliver 10W of output power when driving an 8 Ohm load, or about 18W @ 4 Ohm. It also features a two-FET preamplifier, two inputs with different sensitivity, a treble-cut control and an optional switch allowing overdrive or powerful treble-enhancement.

Guitar Amplifier Circuit Diagram

Parts:

P1______________4K7 Linear Potentiometer
P2_____________10K Log. Potentiometer
R1,R2__________68K 1/4W Resistors
R3____________220K 1/4W Resistor
R4,R6,R11_______4K7 1/4W Resistors
R5_____________27K 1/4W Resistor
R7______________1K 1/4W Resistor
R8______________3K3 1/2W Resistor
R9______________2K 1/2W Trimmer Cermet
R10___________470R 1/4W Resistor
R12_____________1K5 1/4W Resistor
R13___________470K 1/4W Resistor
R14____________33K 1/4W Resistor
C1____________100pF 63V Ceramic Capacitor
C2____________100nF 63V Polyester Capacitor
C3____________470µF 35V Electrolytic Capacitor
C4____________220nF 63V Polyester Capacitor (Optional, see Notes)
C5_____________47µF 25V Electrolytic Capacitor (Optional, see Notes)
C6______________1µF 63V Polyester Capacitor
C7,C8,C9,C10___47µF 25V Electrolytic Capacitors
C11____________47pF 63V Ceramic Capacitor
C12__________1000µF 35V Electrolytic Capacitor
C13__________2200µF 35V Electrolytic Capacitor
D1_____________5mm. Red LED
D2,D3________1N4004 400V 1A Diodes
Q1,Q2________2N3819 General-purpose N-Channel FETs
Q3____________BC182 50V 200mA NPN Transistor
Q4____________BD135 45V 1.5A NPN Transistor (See Notes)
Q5____________BDX53A 60V 8A NPN Darlington Transistor
Q6____________BDX54A 60V 8A PNP Darlington Transistor
J1,J2________6.3mm. Mono Jack sockets
SW1____________1 pole 3 ways rotary switch (Optional, see Notes)
SW2____________SPST Mains switch
F1_____________1.6A Fuse with socket
T1_____________220V Primary, 48V Center-tapped Secondary 20 to 30VA Mains transformer
PL1____________Male Mains plug
SPKR___________One or more speakers wired in series or in parallel, Total resulting impedance: 8 or 4 Ohm, Minimum power handling: 20W

Notes:

SW1 and related capacitors C4 & C5 are optional.
When SW1 slider is connected to C5 the overdrive feature is enabled.
When SW1 slider is connected to C4 the treble-enhancer is enabled.
C4 value can be varied from 100nF to 470nF to suit your treble-enhancement preferences.
In all cases where Darlington transistors are used as the output devices it is essential that the sensing transistor (Q4) should be in as close thermal contact with the output transistors as possible. Therefore a TO126-case transistor type was chosen for easy bolting on the heatsink, very close to the output pair.
To set quiescent current, remove temporarily the Fuse F1 and insert the probes of an Avo-meter in the two leads of the fuse holder.
Set the volume control to the minimum and Trimmer R9 to its minimum resistance.
Power-on the circuit and adjust R9 to read a current drawing of about 25 to 30mA.
Wait about 15 minutes, watch if the current is varying and readjust if necessary.

Technical data are quite impressive for so simple a design:
Sensitivity:
30mV input for 10W output
Frequency response:
40 to 20KHz -1dB
Total harmonic distortion @ 1KHz and 10KHz, 8 Ohm load:
below 0.05% @ 1W, 0.08% @ 3.5W, 0.15% at the onset of clipping (about 10W).

Wednesday, October 8, 2014

Low Cost Fire Alarm Circuit and explanation Using Transistor

Transistor BC177 (Q1) is used as the fire sensor here. When the temperature increases the leakage current of this transistor also increases.The circuit is designed so that when there is an increase in the leakage current of Q1, transistor Q2 will get biased. As a result when there is a fire breakout the transistor Q2 will be on. The emitter of Q2 (BC 108)is connected to the base of Q3(AC 128). So when Q2 is ON Q3 will be also ON. The transistor Q3 drives the relay which is used to drive the load ie,light,bell,horn etc as an indication of the fire. The diode D1 is used as a free wheeling diode to protect it from back EMF generated when relay is switched.

Notes:

The Preset R1 can be used to desired temperature level for setting the alarm ON.
This is not a latching alarm,ie; when the temperature in the vicinity of the sensor decreases below the set point the alarm stops.
The circuit can be powered using a 9V battery or a 9V battery eliminator.
All capacitors are electrolytic and must be rated at least 10V.
The load can be connected through the C,NC,NC points of the relay according to your need.
The calibration can be done using a soldering iron,and a thermo meter. Switch ON the power supply.Keep the tip of soldering iron near to the Q1.Same time also keep the thermometer close to it.When the temperature reaches your desired value adjust R1 so that relay gets ON.

Saturday, October 4, 2014

500W low cost 12V to 220V Inverter

Using this circuit you can convert the 12V dc in to the 220V Ac. In this circuit 4047 is use to generate the square wave of 50hz and amplify the current and then amplify the voltage by using the step transformer.

Attention: This Circuit is using high voltage that is lethal. Please take appropriate precautions

How to calculate transformer rating

The basic formula is P=VI and between input output of the transformer we have Power input = Power output

For example if we want a 220W output at 220V then we need 1A at the output. Then at the input we must have at least 18.3V at 12V because: 12V*18.3 = 220v*1

So you have to wind the step up transformer 12v to 220v but input winding must be capable to bear 20A.

Sunday, September 21, 2014

500W low cost 12V to 220V inverter

Circuit diagram
author: Ashad Mustufa
e-mail: mustufa66@hotmail.com
web site: http://www.electronics-lab.com

How to calculate transformer rating
The basic formula is P=VI and between input output of the transformer we have Power input = Power output
For example if we want a 220W output at 220V then we need 1A at the output. Then at the input we must have at least 18.3V at 12V because: 12V*18.3 = 220v*1
So you have to wind the step up transformer 12v to 220v but input winding must be capable to bear 20A.

Friday, September 5, 2014

Low Ripple Regulated Power Supply Wiring diagram Schematic

This schema may be used where a high current is required with a low ripple voltage (such as in a high powered class AB amplifier when high quality reproduction is necessary ).

Low Ripple Regulated Power Supply Circuit Diagram

PARTS LIST
R1	2.2KΩ 1W
R2	56Ω 1W
R3	1oKΩ 1W
C1	1000µF 63V
C2	100µF 50V
C3	470µF 50V
D1, D2, D3, D4	6A Bridge Rectifier
D5	500mA Zener Diode (see description)
Q1	2N3055
Q2	2N3054

Q1, Q2, and R2 may be regarded as a power darlington transistor. D5 and R1 provide a reference voltage at the base of Q1. D5 should be chosen thus:
D5=V_out-1.2

C2 can be chosen for the degree of smoothness as its value is effectively multiplied by the combined gains of Q1/Q2, if 100µF is chosen for C2, assuming minimum hef for Q1 and Q2,

C=100×15(Q1)×25(Q2)

=37000µF.

Friday, August 29, 2014

Dimmable Low Battery Indicator Wiring diagram Schematic

The schema of battery indicator consists of a 741 operational amplifier configured as a voltage comparator, using a zener diode as a reference voltage pattern. This schema can be adapted to work with battery between 6 and 18 V, and the only changes required would be a lower Zener voltage and current limit resistor in the case of low voltage below 9 V and greater for higher voltages.The adjustment is made with R2 which can be a trim pot.

Dimmable Low Battery Indicator Circuit Diagram

Tuesday, August 19, 2014

Basic Low Pass Filter

Low pass filter is a low-pass filter with low frequency signals but attenuates (reduces the amplitude of) signals with frequencies higher than cutoff frequency. The actual amount of damping for each frequency varies from filter to Filtering.

Sometimes called-high-cut filter, or treble cut filter when used in audio applications. Low-low pass filter is the opposite of the band-pass filter.

Low Pass Filter Basic Circuit

The concept of low-pass filter exists in many forms, including electronic circuits (like a hiss filter used in audio), digital algorithms for smoothing data sets, acoustic barriers, blurring the image, and so forth.