Posts Tagged ‘circuits’

New product alert – solder guns and soldering irons now in stock!

Saturday, June 4th, 2011

We hope you’re going to be just as excited as we are! West Florida Components is now carrying a line of solder guns and irons! You can choose from a battery operated 15W solder iron  (perfect for marine repairs on in the field projects) all the way up to a 150W dual heat full featured gun. All the electric soldering irons and guns are proudly made in the USA by Wall Lenk Corporation and they are guaranteed for 5 full years.

All of the soldering equipment can be used for a wide range of projects, from electronics to lawn and garden equipment….and cutting and smoothing jobs like leather and wood burning.

Most of the guns and irons in stock are ‘kits’ – that is, they come with multiple solder tips and a supply of rosin core solder to get you started on your soldering projects. Are you just learning how to solder? Check out our guide on the basics of “How to Solder” which gives plenty of pointers for soldering newbies.

What is a heatsink?

Sunday, October 26th, 2008

When current flows through a resistor, part of the electrical energy is converted into heat that gets dissipated into the surroundings. If the heat generated is not quickly removed, it can permanently damage the electronic circuit. Heatsinks are devices that are capable of removing the heat from electronic devices and speedily dissipate it into surroundings.

Heatsinks can be passive or active devices. Passive heat sinks consist of fins made generally

Voltage Regulator in a Heatsink

Voltage Regulator in a Heatsink

of aluminum that provide a large surface area for heat dissipation. Active devices in addition have fans that circulate the air around the sink for faster removal of heat. The heat dissipation in a heatsink takes place principally through convection either natural or forced.

Heat transferred through convection is proportional to the temperature difference between the heatsink and the surroundings. The constant of proportionality is called convection coefficient. Mathematically, q = h x A x ∆t, where q is the heat dissipated by convection, h is the convection heat transfer coefficient, A is surface area and ∆t is the temperature difference between the heat sink and the surroundings. The coefficient h is a function of velocity of air circulating around the heatsink among other things. Thus higher the speed of air circulating around the heatsink faster is the heat dissipation.

Heatsinks are widely used for cooling electronic devices and the surrounding circuit like the CPU in a computer. With the need to make electronic devices more compact and powerful, the need to make high capacity heatsinks is increasing. Modern heatsinks are manufactured by extrusion, die casting, cold forging etc. Heat pipes have been used in heatsinks as they are lighter and more efficient compared to solid pipes of same size. Anodized aluminum is the most common material used in making heatsinks, although copper, silver and even gold have been used.

What is Transistor-Transistor-Logic – TTL?

Sunday, September 7th, 2008

TTL Transistor-Transistor-Logic

TTL Transistor-Transistor-Logic


TTL or Transistor-Transistor Logic is a type of digital circuit that is made from BJT or bipolar junction transistor along with resistors. Both the amplifying function and the logic gating function are carried out through transistors, thus the name transistor-transistor logic.

TTL is used for many applications like industrial controls, computers consumer electronics, test equipment, synthesizers and more. The TTL designation is also used in some places to imply ‘compatible logic levels’ even if they are not directly associated with transistor transistor logic circuits.

James Buie invented the Transistor Transistor Logic in 1961 and the first Transistor-Transistor Logic devices were made in 1963 in Sylvania. These devices were called the “Sylvania Universal High-Level Logic family” and were used within controls for the US Phoenix missile. In 1964 Texas Instruments produced ICs of 5400 series and later on, the 7400 series which made the Transistor-transistor Logic devices popular amongst electronic system designers. The 7400 series went on to become the industry standard. Many companies like AMD, Motorola, Intel, Fairchild, Siemens, National Semiconductor made compatible parts.

The TTL circuits were low cost which made them highly practical for using digital techniques in tasks which were earlier done through analog methods. One of the first computers that was built, in 1971, made use of the transistor transistor logic instead of a microprocessor chip which at that point of time was not available. With time incremental improvements in power consumption and speed were made, and the last popular series was the 74AS/ALS Advanced Schottky was made available in 1985.