30-watt stereo amplifier with TDA4935

The amplifier is now offer stereo and Class B is designed with the TDA4935 from Siemens, which delivers 15 watts per channel. Can also be configured in BTL or bridge, thus providing 30 watts in mono.

His power depends on the output impedance, ie if you put a 8 ohm speaker, will be supplied with a minimum of 8 and a maximum of 32 volts for this design we chose 24 volts, as recommended in the datasheet ; if placed unabocina 4 ohms, as in our case, the maximum voltage to be applied is 24 volts. It should be mentioned that the ideal supply voltages are at least 8 and a maximum of 26, to guarantee the life of the integrated circuit.

This amplifier has the characteristic of utlized few external components, making it easy to assemble, capacitors and 2 resistors 9

At the moment we do not offer the PCB, but the data sheet can be seen both in design and in BTL stereo configuration, bridge or bridge.

In the BTL configuration you will get a 60 watt amplifier with the assembly of 2.

 

 

 

Parts list :

 

capacitor:

 

C1, C2, C3, C4: 220 nF. ceramic capacitors

C5, C6, C8: 1000 µF. 35v  ,   electrolytic capacitor

C7: 100 µF. 35 volt  , electrolytic capacitor

C9: 100 nF. ceramic capacitors

Semiconductores:

IC1: TDA4935

R1, R2: 1 Ω 2 watt

Other :

Speakers 4 Ω 30 watt

Supply of 13.5 volts

SW1: Switch 1 pole 1 position.

 

Audio video transmitter am fm radio transmitters

When we started in electronics, the first thing I think most, is to assemble a transmitter. In my beginnings, my first transmitter is performed by using the local oscillator of a radio receiver, logando a range of 500 meters, in amplitude modulated.
If you like radio and TV broadcasts, here I include these audio and video transmitters (limited), FM and medium wave.  It is important to be careful regarding the transmission of radio signals, in many countries this is illegal, therefore these circuits are low power so as not to interfere with any radio or TV. These are so you can experience.

STR-A6000 Power IC for PWM Type Switching Power Supply

General Descriptions
The STR-A6000 series products are power ICs for switching power supplies,
incorporating a power MOSFET and a current-mode type PWM controller  IC.  The low
standby power is accomplished by the automatic switching between the PWM operation in
normal operation and the burst-oscillation under light load conditions. The product
achieves high cost-performance power supply systems with few external components.

 Features
*  Current-Mode Type PWM Control
*  Built-in Random Switching Function
The function reduces the EMI noise and enables a simplified (low-cost) EMI filter,
by the slight- random-change of PMW frequency fOSC.
*  Auto-Standby Function: The burst-oscillation enables the low standby power. Input Power PIN < 25mW at no load
*  Built-in Startup Circuit, enabling low power consumption
*  Brown-In / Brown-Out Function
The function enables the oscillation start/stop by externally rated input voltage and makes protections at low input
voltage.
*  Overcurrent Protection (OCP) with Built-in Input Compensation Circuit: 
The protection has less AC input voltage dependency.
*  Overload Protection (OLP) with Built-in Delay Timer
*  High Speed Latch Release Function
The function releases the latch immediately at AC supply OFF, after the latch protection operation.
*  Bias-Assist Function, reducing Operating VCC voltage drop
The function improves the startup operation and makes a low VCC capacitor applicable.
*  Leading Edge Blanking Function
*  Slope Compensation Function
*  Built-in Avalanche Energy Guaranteed High-Voltage Power MOSFET
*  Various Protections
 Overcurrent Protection (OCP)--------------------------------- Pulse-by-Pulse
 Overload Protection (OLP) ------------------------------------ Auto-Restart
 Overvoltage Protection (OVP) -------------------------------- Latch Shutdown
 Thermal Shutdown Protection (TSD) ------------------------ Latch Shutdown

 Applications
*  Battery Chargers; Mobile Phones, Digital Cameras, Camcorders, Electric Shavers, Emergency/Inducement Lights etc.
*  Standby Power Supplies; LCD-TVs, PDP-TVs, Desk-Top PCs, LBPs, Audio Equipment, etc.
*  Small SMPSs; Ink Jet Printers, BD/DVD Players, CD Players, Set-Top-Boxes, etc.
*  Auxiliary Power Supplies for Controllers; Air Conditioners, Refrigerators, Washing Machines, Dish Washers, etc

  Product Lineup

Note 1: The maximum output power is derived from thermal specifications. The actual output power may be
available around 120 –140% of the above values, respectively, but may be limited by ON duty setting on
transformer design or lower output voltage.

download original datasheet

resistor calculator

Resistor Calculator 1.0

 

Features of Resistor Calculator at a glance:

• Calculating the color code of a resistor value.
• Calculating the resistor value of a color code.
• Displaying the closest resistor of the E series and Renard numbers.
• Resistor calculation for LED circuits (single, in series, parallel).
• Integrated help system.
• Automatic program updates.
• Multilingual (at the moment English and German).
• Intuitive program interface.
• Free e-mail support in case of problems or questions.
• All updates for free.

>> Download Resistor Calculator <<

source :http://www.ab-tools.com/English/software/resistorcalculator/

Night (dark) and a light emitting diode lights.

Night (dark) and a light emitting diode lights.
I think that can be produced easily by using fewer parts.

Schematic

 Once the device for adjusting the light like fireflies.  Turning the adjustment can be variable resistors. Try turning slowly from side to side to bring the device to the variable resistor dark room.  The glowing light-emitting diode. Try moving the unit next to a bright room. If the adjustment is made completely light-emitting diodes should disappear.



 Circuit description
 This circuit has become the focus of three basic parts. CdS and the light hits, the transistor becomes smaller internal resistance is the addition of B and C negative voltage E between the current flow. So do not light emitting diodes.  But the bigger CdS resistance to light exposure and internal voltage plus the addition of B to become a trigger that C, E between the current flows, it is not a light emitting diode.

Parts required for production

Transistor	2sc1815	× 1
Rheostat	Ω 100KΩ	× 1
Resistor	Ω 100Ω	× 1
CdS		× 1
Light emitting diode	Green	× 1
Board	Appropriate sized	× 1
Battery holder	For single- III	× 1
Battery snap	Single-III	× 1

Helmet Cam – Swann Goes Shockproof with the Head-Mounted Sportscam

This is another one for those of you who like the outdoors but love your tech. The Swann head-mounted sportscam is shockproof, waterproof, and offers incredible functionality at a bargain price. So if you want to record your most adventurous outdoors adventures this is the puppy for you… unless you want HD.

No, this camera won’t give HD (or anywhere near it) and is limited to 640 X 480. However, the fact that you can cram 5 hours of footage on a little 16GB microSD card is nothing to sneeze at. That’s long enough for a bike ride up and down the mountain. Unfortunately, the rechargeable battery is only good for 2.5 hours so somewhere in there you have to rest for a recharge. Still, 2.5 hours of recording at a whack isn’t bad.

While the camera is intended to be (or at least works best when) head-mounted you’ll find a bunch of other accessories in the box so you can rig up your own customized mounting options if you wish. You can even use the camera outside its protective waterproof housing if you desire.

You wouldn’t expect to pay much for a camera with such low resolution in the days of the HD obsessed and you won’t have to. $99 gets you one of these when they go on sale in the US next month. You can save the rest of your cash to actually plan a vacation during which to use the camera.

Samson’s USB Meteor Mic is Far From Boring

If you take pride in your computing prowess the last thing you want cluttering up your desktop is a boring old generic microphone. But how do you give your workspace a little more style and class without shelling out tons of cash? Consider the new Meteor Mic from Samson. Designed to look like an “old skool” microphone from the glory days of radio and the birth of Television, this mic has that classic stainless steel look and “egg-shape” chassis. But it is a microphone and all that style isn’t worth a dime if it doesn’t perform, right?

You don’t have to worry about that. While the Meteor Mic won’t outdo some high-end mics in the field of fidelity, it will serve reliably and a few modern features. The first of which you’ll notice is the little tripod on which the mic rests. Those legs close up when the mic isn’t in use and make it ultra-portable (they even include a velveteen carry case!)


However, a little more exciting is the 1.8 inch headphone port you’ll find built right into the mic. You can monitor your own recordings in real time and now what they’ll sound like before you ever play them back.

The mic is also driver-free so you don’t have to worry about software compatibility ruining your recordings.

The mic is a little more pricey than a generic one but still within reason at just under $100.

For full specs and info, visit the official Samson Audio website.