Connecting Two or More Transistors in Parallel

<div dir="ltr" style="text-align: left;" trbidi="on"> How to Connect two or more transistors in parallel<br /><br />While making power electronic circuits, configuring the power output stage correctly becomes very crucial.<br /><br />These stages primarily may consist of power devices like the power transistors or MOSFETs.<br /><br />Using power transistors are more common due to the greater ease of  configuring them. However when higher outputs are desired, it becomes necessary to add more number of these devices together.<br /><br />And as per the rules, it becomes necessary to connect them in parallel. Though using transistors in electronic circuits is pretty easy, connecting them in parallel needs some attention due to the one significant drawback with transistor characteristics.<br /><br />As per transistor specs, the devices needs to be operated under reasonably cooler conditions and that's why we install heatsinks on them to maintain the above criterion. Moreover, transistors have the "bad habit" of conducting proportionately rising currents through them as they get heated up.<br /><br />Therefore if its case temperature tends to increase, the current through it also increases, which in turn heats it up further. The process may get aggravated until the devices become too hot to sustain and gets permanently damaged. This situation is called thermal runaway, in transistors.<br /><br />When connected in parallel, due to non-consistent characteristics, the transistors in the group may dissipate varying amounts of current through them. Consequently, the transistor which passes more current through it starts getting heated up faster and pretty soon we find the device entering into the above thermal runaway situation  damaging itself and promoting the phenomenon to the remaining devices in due course of time.<br /><br />The situation can be effectively tackled by adding a small value resistor at the emitter of each transistor connected in parallel. The resistor inhibits and controls the amount of current passing through the transistors and never allows it to go to dangerous levels.<br /><br />The value should be appropriately calculated, as per the magnitude of the current passing through them.<br />How it's connected? See the figure below.<br /> <div class="separator" style="clear: both; text-align: center;"> <a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiK3ncEjfJ5hVyyB89Zusr8pU-ysk4S55BupHpt50ZOZGYiVvC-Q_vradPFxdcb9HrCrsyX5zkU6NQZU7lsr4kCiVztGqvtmDPtE4ykou3q3ve8p5-8pRxutnuBzD1abppx7GRz6NJwQLo/s1600/How+to+Connect+Transistors+in+Parallel.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="320" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiK3ncEjfJ5hVyyB89Zusr8pU-ysk4S55BupHpt50ZOZGYiVvC-Q_vradPFxdcb9HrCrsyX5zkU6NQZU7lsr4kCiVztGqvtmDPtE4ykou3q3ve8p5-8pRxutnuBzD1abppx7GRz6NJwQLo/s1600/How+to+Connect+Transistors+in+Parallel.png" width="230" /></a></div> <br /></div>

Connecting Two or More Transistors in Parallel

How to Connect two or more transistors in parallel While making power electronic circuits, configuring the power output stage correctly bec...

Read more »

How to Make a Dual Tone Siren Circuit

<div dir="ltr" style="text-align: left;" trbidi="on"> This electronic siren gives out a continuously varying high amplitude sound. Since the supply voltage is not critical, it can be used in cars, motor cycles or at home. It can replace the ordinary call bell. - . The circuit consists of two separate free running multivibrator and an oscillator.<br /> <br /> More innovative circuits HERE.<br /> <br /> A free running or astable multivibrator is one which has two quasi-stable states and the output of one stag is connected to the input of the other through a coupling capacitor.Since both the states are quasi-stable, the output attained is continuously varying in nature i.e. high, low high low-.<br /> <br />  The output is in the form low pulses, the frequency of which depends on the base biasing resistor and the coupling capacitor, When these resistances and condensers for both the stages are of different values, the output ` wave form is rectangular; this is because the time constant of the two quasi-stable states becomes different.<br /> <br /> If this time constant of the two, states is made the same, the output obtained then is square wave. Two states of the multivibrator are made identical by the use of the same values of components.<br /> <br /> The components used in the circuit (Fig). result in a square wave output and the time constant selected is so as to give a fairly good rise and fall of the siren.<br /> <br /> However, one may change the value of coupling capacitors to get any other desired time constant. The second unit is an oscillator section. The condenser connected at the output is the feed back condenser. It determines the tone of the siren.<br /> <br /> Higher the value of the condenser the lower is the pitch. for high pitch sound (generally used in siren) feed-back condenser ranging from 0.047 uf to 0.1 mfd should be selected. The speaker may be metallic case (horn type) or small planer cone. The metallic cone horn gives better results.<br /> <table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody> <tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj9wwMv-vrMSorOob_HJMsjBgRMqpwXmJZokGnHxpbvirywaBMTP4AmDqA5VQG0o7bBnj9mMh4J8TNgKsI-F0s9ZTD7ncNtauXbHSPYa26jMns4sLbIXkHe9TUBrxXNxBNr6dTcldhQcNY/s1600/DUAL+TONE+SIREN+CIRCUIT.png" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="486" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj9wwMv-vrMSorOob_HJMsjBgRMqpwXmJZokGnHxpbvirywaBMTP4AmDqA5VQG0o7bBnj9mMh4J8TNgKsI-F0s9ZTD7ncNtauXbHSPYa26jMns4sLbIXkHe9TUBrxXNxBNr6dTcldhQcNY/s1600/DUAL+TONE+SIREN+CIRCUIT.png" width="640" /></a></td></tr> <tr><td class="tr-caption" style="text-align: center;"><span style="font-size: small;">Dual Tone Siren Circuit </span></td><td class="tr-caption" style="text-align: center;"><br /></td><td class="tr-caption" style="text-align: center;"><br /></td><td class="tr-caption" style="text-align: center;"><br /></td></tr> </tbody></table> <h3 style="text-align: left;"> Parts for dual tone siren circuit</h3> <div style="text-align: left;"> R1,R2,R5,R6= 22K<br />R3,R4 = 2K2<br />R7 = 10 Ohms, 1 watt<br />C1,C2,C4 = 0.1uF<br />C3 = 22uF/25V<br />T1,T2 = BC557<br />T3 = BC547<br />T4 = 2N2907 or 8550</div> </div>

How to Make a Dual Tone Siren Circuit

This electronic siren gives out a continuously varying high amplitude sound. Since the supply voltage is not critical, it can be used in ca...

Read more »

Precision Rectifier, Direct Coupled Power, CMOS Power Booster Circuit Diagrams Explained

<div dir="ltr" style="text-align: left;" trbidi="on"> <div style="text-align: justify;"> The following couple of circuit diagrams provide a glimpse of the configuration for making a precision rectifier and direct coupled power source circuits. </div> <div style="text-align: justify;"> <br /></div> <table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody> <tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjOzFteabrqIkscpz7-naiRECYKfjUgUBi_Z6hgvcc6GVGjFT-x6wRMghbxS5V3Qdz0hec4u-qxqfEdHeQ4zDTdq7n1ikVpD9eFltNdnM6_elMsVxNYE3_3UVPnz4Sytx9nSgUaOn88fBc/s1600/Precission+Rectifier+circuit+diagram..jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="259" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjOzFteabrqIkscpz7-naiRECYKfjUgUBi_Z6hgvcc6GVGjFT-x6wRMghbxS5V3Qdz0hec4u-qxqfEdHeQ4zDTdq7n1ikVpD9eFltNdnM6_elMsVxNYE3_3UVPnz4Sytx9nSgUaOn88fBc/s1600/Precission+Rectifier+circuit+diagram..jpg" width="640" /></a></td></tr> <tr><td class="tr-caption" style="text-align: center;"><span style="font-size: small;">Precission Rectifier circuit diagram.</span></td></tr> </tbody></table> <table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody> <tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhPby5dGzJS3DVQkbeL-swsHamrn3YKzYJ0xCD5H6Au2AdtnsgKesgkfoYMrp-ABffS3dYZVlxilGdOoF0SHIma3qhIWw9A55NmAa48vKEcWFRn3NgsEVojjzfX1Xn4rAFWqFarbxajVRk/s1600/Direct+Coupled+Power+Circuit+Diagram.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="394" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhPby5dGzJS3DVQkbeL-swsHamrn3YKzYJ0xCD5H6Au2AdtnsgKesgkfoYMrp-ABffS3dYZVlxilGdOoF0SHIma3qhIWw9A55NmAa48vKEcWFRn3NgsEVojjzfX1Xn4rAFWqFarbxajVRk/s1600/Direct+Coupled+Power+Circuit+Diagram.jpg" width="640" /></a></td></tr> <tr><td class="tr-caption" style="text-align: center;"><span style="font-size: small;">Direct Coupled Power Circuit Diagram</span></td></tr> </tbody></table> <div class="separator" style="clear: both; text-align: center;"> <br /></div> <table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody> <tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiZUzWKfZFfjgAiYfAPWN4cPKTSfKDjRq7p7u7jxXpLdNr99t0Bu6iDBVsJojKq4_cN8VsSurwDUHufgyXSZ0Z4eGpA46Lt54fnE429X2kRUnjrZKX0gsrNwlh6bZbZDf4eJqp0dQoMhEw/s1600/CMOS+Power+Booster+Circuit+Diagram.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="470" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiZUzWKfZFfjgAiYfAPWN4cPKTSfKDjRq7p7u7jxXpLdNr99t0Bu6iDBVsJojKq4_cN8VsSurwDUHufgyXSZ0Z4eGpA46Lt54fnE429X2kRUnjrZKX0gsrNwlh6bZbZDf4eJqp0dQoMhEw/s1600/CMOS+Power+Booster+Circuit+Diagram.jpg" width="640" /></a></td></tr> <tr><td class="tr-caption" style="text-align: center;"><span style="font-size: small;">CMOS Power Booster Circuit Diagram</span></td></tr> </tbody></table> <div style="text-align: justify;"> The MC1556 operational amplifier way be used as a voltage follower ln a hid; amplifier application. The high input impedance avoids loading effects on the bridge and transforms the impedance down to a level where a third amplifier used in a differential mode can provide voltage gain, ll) in this case. The third amplifier employs the standard offset adjust circuit to provide nulling capability for the configuration. Although the circuit is shown for complementary supply voltages, , it lends itself well to operation from a single supply since the bridge can be operated iust as well from the single supply. One must, however,,provide for biasing the nowgrounded 100 kS2 resistor to half the supply voltage using a simple resistive divider. Also.- of course, the output is no longer referenced to ground, but to half the supply voltage. In the circuit the output from an LM3900 N amplifier is fed to a Darlington pair of power transistqrs. can deliver over three a suitable load when the are correctly mounted on The current·sourcing and sinking capability of the CA513O output stage is easily supplemented to pro- vide powenboost capability. ln the ' circuit three COS/MOS transistor- pairs in a single CA36OOE IC array are shown parallel connected with the output stage in the CA5l30. Jn the Class A mode of CA36OOE shown, a typical device consumes 20 mA of supply current at 1 5V operation. This arrangement boosts the current- handling capability of the CA3l3O output stage by about 2.5.courtesy - ETI Electronics   </div> </div>

Precision Rectifier, Direct Coupled Power, CMOS Power Booster Circuit Diagrams Explained

The following couple of circuit diagrams provide a glimpse of the configuration for making a precision rectifier and direct coupled power ...

Read more »

CadSoft Eagle Professional 6.5.0 Multilingual | 44.27 MB

<div dir="ltr" style="text-align: left;" trbidi="on"> Image<br />CadSoft Eagle Professional 6.5.0 Multilingual | 44.27 MB<br /><br />EAGLE (Easily Applicable Graphical Layout Editor) is an ECAD program produced by Cadsoft in Germany. It is very commonly used by private electronics enthusiasts, because there is a very usable free demo version for nonprofit use and is available in English and German. Cadsoft has released versions for Microsoft Windows, Linux, and Mac OS X. EAGLE provides a schematic editor, for designing circuit diagrams and a tightly integrated PCB layout editor, which automatically starts off with all of the components required by the schematic. Components are manually arranged on the board, with the help of coloured lines showing the eventual connections between pins that are required by the schematic, to aid in finding a placement that will allow the most efficient track layout.<br /><br />It also provides a good autorouter, which once the components have been placed will attempt to automatically find an optimal track layout to make the electrical connections. It does not always manage to find a way of routing all the signals, although it permits manual routing of critical paths such as power and high frequency lines before letting the autorouter handle the other connections.<br /><br />EAGLE is very popular with hobbyists because the free demo is able to create usable PCBs. (Free ECADs from some companies are crippled so that they won't save or won't print.) The only limitations of boards made with the EAGLE demo are: 2 copper layers; a maximum size of 80mm x 100mm (½ Eurocard)(~3in x ~4in). The demo version of the schematic editor module can only create single-sheet schematics.<br /><br />The licensing structure for the commercial version is very flexible. In order to use the demo version to make commercial products, it must be licensed for $49 USD. If more is needed, it is also possible to license the required extra modules (schematic capture, layout, autorouter) separately and simply purchase more if needs change.<br /><br />What's new in version 6:<br /><br />Read, edit and parse the data outside of the EAGLE tool<br />The new XML database structure provides the ability to write scripts that manipulate designs in the EAGLE format which will give users huge productivity benefits. You can make design changes, import information from other designs, and even translate from other formats. EAGLE is one of the first Commercial CAD Programs that adopts a ASCII XML data structure as their native file. This makes EAGLE the most flexible, user friendly and productive PCB tool on the market.<br /><br />Merge board/schematic pairs using the PASTE function with full consistency<br />You can copy an already finished design consisting of a consistent pair of Schematic and Layout into another project. Enumeration of components and signals will be exactly the same in board and schematic, so that consistency between schematic and board will be maintained. This supports easy design, for example, of multi-channel devices. You only have to design schematic and layout for one channel and can copy it easily.<br /><br />Optimize your work-flow with Undo/Redo log<br />The UNDO/REDO log shows the history of each step you have made. You have full control of the steps going back or forward.<br /><br />Work with flawless conversions between mm and inches through increased internal resolution (allows grids of 1/4, 1/8, 1/16,1/32 and 1/64 mil)<br />If you have to work with both systems, metric and imperial, you know about problems that can arise in converting the usual imperial grid values (always divided by 2) and the resulting mm values. Increasing the internal resolution up to 1/64 mil will allow a proper conversion in all situations.<br /><br />Benefit from differential pair routing and automatic meanders<br />Special signals can be routed with exactly the same length. Differential pair routing is used for pairs of differential (equal and opposite) signals across the board to create a balanced transmission system. Creating meanders helps users automatically give a signal a certain length in the PCB. Meanders in traces are used to increase delay times in high speed digital circuits.<br /><br />Improve your efficiency through BGA escape routing (ULP)<br />BGA devices can have a 1000 connections or more. Packages are getting smaller and smaller. It is a hard and tedious work to connect all the pins, set vias, decide about the layers to use, and come out from the BGA area. This ULP helps you in escaping from the BGA in a proper way.<br /><br />Connect a pin to multiple pads<br />You can now connect one pin in the schematic symbol to any number of pads of the package. With this function EAGLE can handle components internal connected pins. Compared to previous versions schematic symbols look nicer and you save time in defining them.<br /><br />Draw arbitrary pad shapes easily<br />Take a pad or an SMD as basis and draw the final contour with the help of the WIRE or POLYGON command. These objects will be considered as part of the pad/smd. No more problems with Design Rules Check for such objects.<br /><br />Benefit from unlimited number of technologies and package variants<br />Until now the maximum number of technologies and package variants was limited. In some cases one could reach the limits and had to split a library into two parts. No more limitation in EAGLE 6.<br /><br />Dimension your layout automatically<br />A dimensioning tool where you decide by a few mouse clicks the objects to be dimensioned.<br /><br />Create restricted areas with Cutout polygons<br />Outer and inner layers can now have individual restricted areas that will be avoided by signal polygons. Simply draw a polygon and define it as cutout.<br /><br />Be flexible with assembly variants<br />One schematic but a number of different assembly variants can be handled now.<br /><br />Justify your text to left, top, right, bottom, middle or center with one mouse click<br />This allows you to adjust texts as you know it from text editors. Gives a neat look and makes writing, for example, comments more comfortable.<br /><br />Individualize your schematics, sheets, boards and symbols with descriptions<br />The file description can inform you about the content of a board or schematic. It is shown in the Control Panel without loading the file in the editor windows. This makes your project management clearer. See what this file contains without loading it in an editor window. This also works with sheets of multi-sheet schematics.<br /><br />Define your own context menu<br />Speed up your work-flow with self-defined content in the context menu. Frequently used commands or combinations of commands can be integrated into the context menu. This minimizes mouse-clicks and increases working speed.<br /><br />LTSpice Simulation<br />Simulate your EAGLE Schematic in LTspice IV, import LT-Spice schematic files and export EAGLE partial or full schematics.<br /><br />Supported OS: Windows XP, Windows Vista, Windows 7, Windows 8<br /><br />Home Page -http://www.cadsoftusa.com/<br /><br />Link Download<br /><br />Secureupload.eu<br />http://www.secureupload.eu/nffnow31d9c5/CadSoft.Eagle.Professional.6.5.0.rar<br /><br />Rapidgator.net<br />http://rapidgator.net/file/0d21dcce9a328223bf418471bbe4b595/CadSoft.Eagle.Professional.6.5.0.rar.html<br /><br />Uploaded.net<br />http://uploaded.net/file/izunofzd/CadSoft.Eagle.Professional.6.5.0.rar</div>

CadSoft Eagle Professional 6.5.0 Multilingual | 44.27 MB

Image CadSoft Eagle Professional 6.5.0 Multilingual | 44.27 MB EAGLE (Easily Applicable Graphical Layout Editor) is an ECAD program produce...

Read more »