Rongge

In building QRP HF radios, having an RF signal level amplifier building block is handy. You want 50 Ohm output impedance, some reasonable gain, supply voltage of the usual 10-14V and ease of building using standard parts from your parts bin. Some searching around the interwebs came up with a good idea for circuit from Aaron Parks, KC8FQD, who did a YouTube video on a WWV receiver. [ ]

General Description: The BA3840KV is a preset graphic equalizer IC for headphone stereos. It combines two equalizer circuit channels ona single chip, and also includes a dynamic sound leak reduction circuit. Circuit diagram: Graphic Equalizer for Headphone Stereos Datasheet for BA3840: Download

With a suitable load, the terminal voltage of a NiCd or lithium-ion battery is proportional to the amount of stored energy. This relationship, which is linear over a wide range, can be used to build a simple battery capacity meter. This model battery tester has two functions: it provides a load for the battery, and at the same time it measures the terminal voltage. In addition, both functions can be switched on or off via a model remote-control receiver, to avoid draining the battery when it is not necessary to make a measurement. The load network, which consists of a BC517 Darlington transistor (T2) and load resistor R11 (15 Ω /5 W), is readily evident. When the load is active, the base of T1 lies practically at ground level. Consequently, T1 conducts and allows one of the LEDs to be illuminated.    Voltage Tester for Model Batteries Circuit Image  Circuit Diagram : Voltage Tester for Model Batteries Circuit Diagram The thoroughly familiar voltmeter circuit, which is bas...

Watching movies is a neat escape from the stressful lifestyle we live in. Watching movies in a wide screen and surround sound take you far away and into the movie scene you are watching. You watch it as if you were there in the movie scene. Of late, we can only experience this escape in a cinema. However, modern technology may be able to provide this same sight and sound experience right in your own living room. We will discuss the basic components of a home theater system in this article. Read on to understand how these basic components can deliver the best cinematic experience to a home theater system. Home theater experts state that the most important consideration in setting up a home theater system is the size of the room where you will set up the home theater system. The most important component of the home theater system, which is the television, is dependent on the size of the room. Although, the recommendation is 27 inches television set at a minimum is necessary for your home...

A project of Telephone for VoIP gate Circuit Diagram. Calls over the Internet can be in several different ways. For households with a permanent connection to the Internet, it is advantageous to use different IP phones and VoIP gateways that need to function on the computer. Because IP phones are still relatively expensive, they are used more often different VoIP gateway. VoIP gateway is "one end" connected to a network with access to the internet, the "other end" connects a standard analog phone, which is then used in the normal way and that has given a telephone number available from any fixed or mobile phone. Some VoIP gateway router in addition to that we need as well, if we want to access via a modem to connect multiple computers. To my VoIP gateway, we can connect nehomologovaný, self made ​​phone. Instructions for simple phone is the subject of this article. How to the phone works Normally the phone line is a DC voltage, usually 50 to 70 V. During the ring...

This circuit is a simple test of USB ports, it is a circuit very useful for anyone working in the field of computer science. To be "stuck" in the PC USB port or an information display Notebook USB device not recognized, just after the yellow LED flashes 3 times, and since it is not a normal USB device, the connection is not established, and micro displays an error message. Tester for USB communication ports Circuit Diagram List of Components 1 Red LED 1 Led Yellow 1 Green LED 3 per 1k 1/8W Resistors 1 USB connector male Simple Test for USB communication ports Indications of LEDs when lit: Red - Polarization USB port was mounted inverted Yellow - Wire USB port data were linked inverted All Deleted - No power to the USB port Green and yellow lights flashing 3 times when turned on - Normal Operation

How to make a Power Line Modem Circuit for Home Automation Application. Imagine you have a master controller device that control other devices in your house, and you don’t need to install any additional wires to facilitate the data communication between the master controller and the controlled devices. Yes you’s life will be easier since all you need is just plugging your devices into your power line outlet, the devices will communicate each-other through the power line while using the line to enpower them! Circuit Diagram:   The secret is the powerline modem, a modem that use the powerline wiring as their media to exchange the data. Philips Semiconductors has a single chip powerline modem solution, a TDA5051A IC chip. Here is the schematic diagram of this powerline modem circuit. The TDA5051A single chip power line modem is equipped with protection of its output power stage and automatic gain control (AGC) of input signal. With simple coupling network, this power line modem is com...