Description

Here’s a single chip FM transmitter circuit using Maxim semiconductors IC MAX2606. The MAX2606 is a compact, high-performance intermediate frequency VCO specially designed for wireless communication circuits. They have monolithic construction with low-noise and a low-power operation in a compact 6-pin SOT23 packing .Th1s low-noise IC feature an on-chip varicap diode and feedback capacitances that avoid the need for external tuning components, making the MAX2606 perfect for portable systems. Only an external inductor is needed to set the oscillation frequency.In addition to this, an
integrated differential output buffer is also there for driving a mixer or prescaler.The MAX2606 can be operated from a single +2.8 V to +5.4V supply and consumes very less current .The chip can be operated from 45MHz to 650MHz .

In the circuit the nominal frequency is set to 100 Mhz by inductor L1, (390nH) . The left and right channel audio signals from your source are added by R3 and R4, and attenuated by the POT R2. R2 can be used as a volume control .POT R1 can be used to select a channel of transmission between 88Mhz and 108Mhz.Use 80 cm long wire as the antenna .

Circuit Diagram with Parts List.

Notes

• Assemble the circuit on a good quality PCB or common board.
• Use a battery for powering the circuit.It will reduce noise.
• An FM antenna from a old radio is a better option than the wire antenna.

Description

This is the cheapest 150 Watt amplifier circuit you can get,I think.Based on two Darlington power transistors TIP 142 and TIP 147 ,this circuit can deliver a blasting 150 W Rms to a 4 Ohm speaker.Enough for you to get rocked?,then try out this.

TIP 147 and 142 are complementary Darlington pair transistors which can handle 5 A current and 100V ,famous for their ruggedness. Here two BC 558 transistorsQ5 and Q6 are wired as pre amplifier and TIP 142 ,TIP 147 together with TIP42  (Q1,Q2,Q3)  for driving the transistors.This circuit is designed so rugged that this can be assembled even on a common board or even by pin to pin soldering.The circuit can be powered from a +/-45V 5A  dual power supply.You must try this circuit.Its working great.

Circuit Diagram & Parts List .

Notes.

• Remember TIP 142 and 147 are Darlington pairs  .They are shown as conventional transistors in figure for ease.So don’t get confused.Even though each of them have 2 transistors ,2 resistors and 1 diode inside ,only three pins ,base emitter and collector are coming out.Rest are connected internally.So its quite OK to assume each of them as transistor for ease.
• Use a well regulated and filtered power supply.
• Connect a 10K POT in series with the input as volume control if you need.Not shown in circuit diagram.

TIP 142 & 147 Internal diagram and pin out.

Description

Here is a 100 Watt inverter circuit using minimum number of components.I think it is quite difficult to make a decent one like this with further less components.Here we use CD 4047 IC from Texas Instruments for generating the 100 Hz  pulses  and four 2N3055 transistors for driving the load.

The IC1 Cd4047 wired as an astable multivibrator produces two 180 degree out of phase 100 Hz pulse trains.These pulse trains are  preamplifed by the two TIP122 transistors.The out puts of the TIP 122 transistors are amplified by four 2N 3055 transistors (two transistors for each half cycle) to drive the inverter transformer.The 220V AC will be available at the secondary of the transformer.Nothing complex just the elementary inverter principle and the circuit works great for small loads like a few bulbs or fans.If you need just a low cost inverter in the region of 100 W,then this is the best.

Circuit Diagram with Parts List.

Notes.

• A 12 V car battery can be used as the 12V source.
• Use the POT R1 to set the output frequency to50Hz.
• For the transformer get a 9-0-9 V , 10A step down transformer.But here the 9-0-9 V winding will be the primary and 220V winding will be the secondary.
• If you could not get a 10A rated transformer , don’t worry a 5A one will be just enough. But the allowed out put power will be reduced to 60W.
• Use a 10 A fuse in series with the battery as shown in circuit.
• Mount the IC on an IC holder.
• Remember,this circuit is nothing when compared to advanced PWM inverters.This is a low cost circuit meant for low scale applications.

Design Tips.

The maximum allowed output power of an inverter depends on two factors.The maximum current rating of the transformer primary and the current rating of the driving transistors.

For example ,to get a 100 Watt output using 12 V car battery the primary current will be ~8A ,(100/12) because P=VxI.So the primary of transformer must be rated above 8A.

Also here ,each final driver transistors must be rated above 4A. Here two will be conducting parallel in each half cycle, so I=8/2 = 4A .

These are only rough calculations and enough for this circuit.

Description.

Here is the circuit of a 2X12 watt HiFi  amplifier circuit using IC TDA 2616 from Phillips.A quiet simple and robust circuit using very less components.This makes the circuit ideal for a portable power amplifier.The circuit delivers 12 W power on  8 Ohm speaker for each channel at +/- 12 V dual supply.

The TDA2616 is a  stereo power amplifier IC comes  in a 9-lead single-in-line (SIL9)
plastic power package (SOT131). This IC is  specially designed for mains
fed amplifier circuits, such as stereo radio,tape  and television .The IC has good gain balance of both channels and Hi-fi in accordance with IEC 268 and DIN 45500 standards.Also the IC TDA 2616 has special inbuilt circuit for the  suppression
of noise signals at the inputs, during switch-on and switch-off.This prevents click sounds during power on and power off.

Circuit Diagram with Parts List. 

Notes. 

• All capacitors except C10 & C9 are ceramic.
• All capacitors must be rated 50V.
• Use a well regulated and filtered +/- 12 V dual power supply that is able to provide at least 2 A continuous current.

TDA 2616 Pin assignment & layout.

Here is a simple and humble mini 2W amplifier suitable for small pocket radios and other portable audio gadgets.The circuit is based on Phillips Semiconductors IC TDA 7052.The amplifier can be run even from a 3V Mercury button cell.This makes it ideal for battery operated gadgets.

The IC TDA7052 is a mono output amplifier comng in a 8-lead DI package (DIP). The device is mainly designed for battery-operated portable audio circuits. The features of TDA 7052 include ,no external components needed,  no switch-on or switch-off click sounds , great overall stability ,very low power consumption(quiescent current 4mA) , low THD, no  heatsinks required and short-circuit proof.

The gain of TDA 7052 is fixed internally at 40 dB. . To compensate the reduction of output power due to low voltage supply  the TDA7052 uses the Bridge-Tied-Load principle
(BTL) which can provide  an output  of around 1 to 2 W  Rms(THD = 10%) into an 8 Ohm load with a power supply of 6 V.

In the circuit the potentiometer can be used to control the volume.Capacitor C1 and C2 are meant for  filtering the supplyvoltage if a battery eliminator is used as supply source.For operations using a battery C1 and C2 are no necessary.

Circuit Diagram with Parts List .

Notes.

• Assemble the circuit on a good quality PCB or common board .
• If you are a little expert, you can assemble the  circuit in a match box including the speaker.