Wiring And Schematic

Sunday, September 14, 2014

Soldering iron temperature controller

In most cases I need the stabilize heat for different components like transistor ,IC’s and other semiconductor devices which cannot abide the heat may be it will be damage . Then I make the simple but the important schema for control the heat of soldering iron.

Circuit diagram:

The schema consists of diac, triac, diodes, resister, potentiometer and capacitor.

Parts List:

R1 = 15 Kilo-Ohm

P1 = 250K potentiometer

C1 = 823K, 250V

D1, D2 = 1N4004 or 1N4007

D3 = Diac, bilateral trigger type

Q1 = Triac 500V/25A, BT136

Circuit Operation:

The schema works on RC time constant. The triac is connected in series with soldering iron the reason of choosing the triac is that it work on any polarity so the MT1 (main terminal one) is connected with live wire of 220VAC and MT2 (main terminal two) is connected with soldering iron heater or any of them the diac is connected in series with the gate of triac. It is use for trigger on the gate the R1 and capacitor C1 is the RC time constant and potentiometer is use for changing the trigger or pulses which control the heat of soldering iron manually. The diodes are just for enhancing the ability of charging and discharging and provide protection to diac.

Soldering Iron Tip Preserver Wiring diagram Schematic

Although 60/40 solder melts at about 200&degC, the tip temperature of a soldering iron should be at about 370&degC. This is necessary to make a good quick joint, without the risk of overheating delicate components because the iron has to be kept on the joint for too long. Unfortunately, at this temperature, the tip oxidises rapidly and needs constant cleaning. Thats where this schema can help - it keeps the soldering tip to just below 200&degC while the iron is at rest. Oxidisation is then negligible and the iron can be brought back up to soldering temperature in just a few seconds when needed. In addition, normal soldering operation, where the iron is returned to rest only momentarily, is unaffected because of the thermal inertia of the iron. Two 555 timers (IC1 & IC2) form the heart of the schema.

Soldering Iron Tip Preserver Circuit diagram:

soldering-iron-tip-preserver

Soldering Iron Tip Preserver Circuit Diagram

IC1 is wired as a monostable and provides an initial warm-up time of about 45 seconds to bring the iron up to temperature. At the end of this period, its pin 3 output switches high and IC2 (which is wired in astable configuration) switches the iron on - via relay RLY1 - for about one second in six to maintain the standby temperature. The presence of the iron in its stand is sensed by electrical contact between the two and some slight modification of the stand may be necessary to achieve this. When the iron is at rest, Q1s base is pulled low and so Q1 is off. Conversely, when the iron is out of its stand, Q1 turns on and pulls pins 2 & 6 of IC2 high, to inhibit its operation. During this time, pin 3 of IC2 is low and so the iron is continuously powered via RLY1s normally closed (NC) contacts. Note that the particular soldering iron that the schema was designed for has its own 24V supply transformer. Other irons may need different power supply arrangements. The warm-up time and standby temperature can be varied by altering R2 and R5, as necessary.

Streampowers

Soldering Techniques

Soldering is a simple efficient and reliable way to make electrical connections. The most common reason people are not successful in making good solder connections (joints) is that they do not properly heat the components which are being soldered. Some people apply the solder only to the tip of the iron. This will most likely result in a cold solder joint. Cold solder joints will almost always fail. The only time that you should apply the solder directly to the iron is when the iron isnt conducting the heat to the parts. When the COMPONENTS being soldered are hot enough to easily melt the solder, you know the components are hot enough to make a good quality solder connection. Be sure to keep the soldering iron clean. The oxidized solder which will start to form on the outer surface of the tip of the iron is an insulator and will prevent good heat conduction to the electronic components. If you use a wet sponge to clean the iron, be very careful. If there is a large quantity of solder on the tip and you press hard on the sponge (compressing it a significant amount), as the iron slips off of the sponge hot solder may be thrown off of the sponge (and it still may be very hot). I think it may be better to use something like a coarse steel wool to clean the iron. I also believe that the wet sponge may significantly reduce the life of the tip.

Selecting a Quality Iron

If you want a really good iron, I would suggest that you buy a Weller WP35 iron. I have used them for a very long time and they are very reliable. A WP35 (approx $35) is a 35 watt iron which is suitable for almost everything that you will need to do in car audio or electronic repair work. DO NOT buy a $5 iron and expect it to last very long. The tips of cheap irons are usually just bare copper which quickly oxidizes and cannot properly conduct the heat to the components. The tips on the WP35 are steel clad copper which last for months at a time, even when they are used for more than 8 hours a day. The tips are also available in different sizes. The wider thicker tips are more suitable for soldering larger components.

Soldering Flux

Flux is used to help keep oxygen out of the connection and helps to float contaminants to the surface. It may also help to conduct the heat to the components. Virtually all solder designed for soldering electronics has a core which contains flux. When buying solder for electronics, make sure the flux is not an acid flux. Acid flux is used to solder non electronic components like sheet metal. Flux is also available in a paste form but I rarely use it.

Desoldering

If you have ever tried to remove electronic components from a circuit board (especially multi legged components), you know that it is difficult to remove the old solder without some help. The 2 least expensive, quickest devices to remove the solder are desoldering braid and the desoldering pump. Desoldering braid is simply a flux coated copper braid usually about .1"-.15" wide. To remove the excess solder with braid, you simply apply heat to the braid while the braid is in contact with the solder. The braid will wick the melted solder from the circuit board. The desoldering pump is a device which creates a vacuum to suck up the melted solder. The one I use has a spring loaded plunger which you cock prior to each use. Then when the solder is melted, put the tip of the desoldering pump on the solder joint and release the plunger by pressing (depressing) the release button. For me, it works better if the iron is left on/in the solder while sucking the solder. This will result in a slightly shorter life of the desoldering tip but I have better results. I would recommend buying a Soldapult brand desoldering pump. A large professional quality model is about $30 and will last a very long time. Ive used mine professionally for about 5 or 6 years and they are still going strong.

Wiring And Schematic

Sunday, September 14, 2014

Soldering iron temperature controller

Monday, September 8, 2014

Soldering Iron Tip Preserver Wiring diagram Schematic

Tuesday, August 19, 2014

Soldering Techniques