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    Strange behaviour of 78xx reg.

    Hi Staigen, yes, you are right, excues me for this, i have too the dictionary, and translator, but not every time i have time for this, but in the future will try to correct may errors. p.s And i have one more problem, i use the HP NX7010, this laptop has a some very strange keyboard, if not...
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    Strange behaviour of 78xx reg.

    Hi, yes, i try to say above to same, not is good idea for any part to work closely to the maxium parameter, in the case with 78xx the surface temperature was 80 C, this is two time lowwer, and i think is acceptable in some cases. About the problem with a regulator and heatsink without bolt and...
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    Strange behaviour of 78xx reg.

    Hi Ante, thanks for the answer, about the temperature yes, if is possible i put the all part in goot temperature condition, if is a possible, i know how temperature reflect over reliability, iuse the Item software for reliability analisys. But sometime, in some case have other reason, price...
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    Strange behaviour of 78xx reg.

    Hi, yes, you a right, but i give this 2-3 W as a value to clculate eventual different between case temperature and crystal temperature, im sure for the case temperature, becose i use a thermometer. The chip separate some power via the PCB. And total power over the chip .... i not remember, in...
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    Strange behaviour of 78xx reg.

    Hi, thanks for th post, i know all this, but i just what to share some my  experiance. About temperature, yes the crystal temperatur is higer, but this is temperature for junction in data sheet, the thermal resistanse junction-case fot TO-220 is a 5 C/W. When the package is 80 C, the junction...
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    Strange behaviour of 78xx reg.

    Hi to all, yes, for my practice i see a several stranges in 78xx behavior. 1. This i think all must know, must have a good frequncy capacitor, ceramic 47 or 100 nF is good, this capacitor must be in input and utput, to prewent oscilation process. 2. The temperatute problem, in NS or ST...
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    driver circuit for a n-channel MOSFET

    Hi, what is the supply of your trigger, and way if you have a uC put this shmid trigger. If the output of your triger not going to 12 V you cn have a problem, actually you wil have a problem, becose your PNP will be open. To control the transistor is used the current Base-Emiter. In your case...
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    Why Sink current is higher than Source current?

    Hi, this is depend from the technology, in some chips have a curent sources, on some chips the limit is from high side structures. Not in every chips have a different between two curents. RTL is a rezistor transistor logic, in this type of logic is a normal to have a much higer current t grond...
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    when should use FPGA?

    Hi, to Ante, one remark, yes the FPGA is not a CPU, but .. i think is not very far from MCU. The princip is different, but in this moment in many FPGA application is used IP core for different procesor, and second, for FPGA is used program languages. About this when you can use FPGA and when...
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    transistor projects

    Hi, i don't think that you have need from project, the transistors is not simple device, you can understood how exactly work from one project. I will upload the file that can help ypu to understood how work the transistor. This is first part, for bipoliar transistors, sory for bad qualiy, but i...
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    Phototransistor circuit

    Hi, yes in the internet has a many circuite diagram, you can look at www.national.com ot wwwintersil.com, and also www.analog.com, in this website you can see different aplication notes. You must have a minde that phototransistor is more sensitive, compared with a photodiode, and is a very easy...
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    Specialized Power Supply

    Hi, you can use the SMPS, some like the LM2575, but with a current feadback. Another choicesh is t use linear regulator, LM317 etc., but in this case the power over the regulator will be higer, for example, if you use 2575, and for 500 mA he voltage over the photodiode is around 3 V, and your...
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    9V power source

    Hi, You can use just one bateries, a 9 V cells, or a 3 LiOn cells, this will give you around 11 V, depent from the current that you will be need have a different possibilities, if can give me us more specific parameters, specially current, we can give you the best decision. p.s. why you use 9...
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    3-5V DC @50mA from 230V AC without transformer

    Hi, in the post above, you can see ones of the possible decision, but this decision has one disadvantage, minimum dispersed power @50 mA is it around 5 W. If you not have a space for a big components, or you want cold device, the better choices is using of SMPS, i can suggest TNY series from...
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    vehicle rpm based switch- help

    Hi, if the output is a digital, PWM or Impulse will be better if you use a microcontroler, PIC10 or PIC12. If the output is analog, you can use simple comparator. One another possibilities is useng a Frequency to Voltage convertor, if the output is a Impulse, and comparator after the...
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    temperature sensor with digital output

    Hi, Yes you can, but must think about input offset voltage, you must make the input compensation. I can suggest to use more precision OPAMP, something like MCP606/7/8/9 from Microchip or OP-41, OP-07 etc.
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    Stepper motor controll

    Hi, dependce form the motor i can suggest yu to use the curent control, in this case the suply voltage for the steper can be 24 ot 48 volts, you will cntrol the current. But if want to test on he low speed may be this is too complex decision. To conol the output voltage you have several...
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    Automate Machine

    Hi MP, you are  very right, for a uC he will need more experience, a PLC may be will be more easy,  but again will need some experience and knowledges that i think he not have. But if using a simple timer and counter modules will need just to make the connection between them and we can give him...
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    Automate Machine

    Hi, I understand that he want to automated all process, the process is complex, first moving role down,bending, moving down, bending .... to the moment when have a required radius of bending. For this reason i think is need something more that switch, but if he use a counter and timer, i think...
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    Automate Machine

    Hi, you have a two possibilities, first is buy a controller, many company have a controllers that work with user software, Siemens, Honeweel, Rockweel etc. this is a PLC controllers. Second way is to make own contorller, but if you want to program time and cycles, you must use microcontroller...
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