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Recent content by fxdif
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Help needed with circuit
it is part of a circuit we use at work for a frequency to voltage converter- fxdif
- Post #6
- Forum: Circuit design
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Help needed with circuit
thanks for your reply, so basically it generates a 100us pulse at 200-10Khz depending on input frequency?- fxdif
- Post #3
- Forum: Circuit design
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Help needed with circuit
Hi, I need some help regarding a circuit operation. I will try to describe it as best I can. Input is a 1:1 pulse train of 200-10Khz. This is fed into one input of a NOR gate. Output goes through a 10nF cap to a pullup resistor of 10K. This also goes through a 10K resistor to another NOR...- fxdif
- Thread
- Replies: 6
- Forum: Circuit design
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+5V Switching Regulator
About £3 was a price I got. I will check out the MAXIM part. Thanks- fxdif
- Post #5
- Forum: Circuit design
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+5V Switching Regulator
The MAX710, MAX711, Micrel mic2570 and the Linear LT1073 look quite reasonable although I'm sure quite expensive. These are the few I have come up with. Just wondering if there are any others?- fxdif
- Post #3
- Forum: Circuit design
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+5V Switching Regulator
Anyone know of a cheap +5V switching regulator with the following spec Vin 1.6 - 7.5V Vout +5V Iout 100mA Many thanks- fxdif
- Thread
- Replies: 6
- Forum: Circuit design
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Measuring Capacitor ripple current
Hi, How can I measure the ripple current through a capacitor? Can I just use an ammeter? Thanks- fxdif
- Thread
- Replies: 2
- Forum: Circuit design
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T-Type flip flop from NAND gates
Is it possible to construct a T-Type flip flop just from NAND gates? TIA- fxdif
- Thread
- Replies: 4
- Forum: Circuit design
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Need help with a transistor
_______________ +5V | | | | _|_ | | | | | | |/ | | /¯ ¯|¯ |/ |________| | |_|_ | | | | | | | _|_ ¯|¯ | | | | | 100R | | | | ¯|¯ \...- fxdif
- Post #3
- Forum: Circuit design
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Need help with a transistor
I want to switch a transistor (as below) that will supply current via the 100R resistor when power is applied. However, I would like to be able to turn the transistor OFF and ON using a micro. Any ideas? _______________ +5V | | | | _|_ | | | | |...- fxdif
- Thread
- Replies: 3
- Forum: Circuit design
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Driving a FET via a micro
Sorry, what I should have put is ________________ +5V | | _|_ | to rest of cct 10K | | | |/ BC857 /|\ | | | /¯ | ¯|¯ |/ |...- fxdif
- Post #18
- Forum: Circuit design
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Driving a FET via a micro
Tried a pull-up but that made no difference. Then tried zeitghosts solution. Took the output from the micro into a PNP transistor (BC857) with 1K resistor on collector to ground. Then used that 'inverted' output to drive my FET. Now it works great. Thanks zeitghost for your comments. I...- fxdif
- Post #12
- Forum: Circuit design
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Driving a FET via a micro
Only have 5V to work from. I'll look into your solution and report back any findings. Many thanks- fxdif
- Post #9
- Forum: Circuit design
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Driving a FET via a micro
Hi, thanks all for your replies. The transistor I am using is a IRLZ34N n type logic level mosfet. The transistor is OK becuase I applied a direct drive to the gate from an external power supply and it switched ok. Reading the data sheet for the ST7 micro it can deliver up to 25mA which I...- fxdif
- Post #7
- Forum: Circuit design
