Recent content by fxdif

it is part of a circuit we use at work for a frequency to voltage converter

thanks for your reply, so basically it generates a 100us pulse at 200-10Khz depending on input frequency?

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...

Thanks all, thats great!

About £3 was a price I got. I will check out the MAXIM part. Thanks

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?

Anyone know of a cheap +5V switching regulator with the following spec Vin 1.6 - 7.5V Vout +5V Iout 100mA Many thanks

Hi, How can I measure the ripple current through a capacitor? Can I just use an ammeter? Thanks

Is it possible to construct a T-Type flip flop just from NAND gates? TIA

_______________ +5V | | | | _|_ | | | | | | |/ | | /¯ ¯|¯ |/ |________| | |_|_ | | | | | | | _|_ ¯|¯ | | | | | 100R | | | | ¯|¯ \...

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 | | | | _|_ | | | | |...

Sorry, what I should have put is ________________ +5V | | _|_ | to rest of cct 10K | | | |/ BC857 /|\ | | | /¯ | ¯|¯ |/ |...

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...

Only have 5V to work from. I'll look into your solution and report back any findings. Many thanks

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...