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Ok managed to capture input sinewave (through 3 series 100k resistors and measuring on the middle one = 1/3 voltage) and output pulses at the same time. Sinewave does not look very good so probably its the harmonics that are messing with the timing. Zooming on the pulse rise/fall time the...

Here is a test using this circuit - https://cdn.hackaday.io/files/1597066832861504/SimpleIsolatedZeroCrossDetector.pdf I have increased the input capacitor to 10nF and added a dual coil filter on the input but still getting around 50us between cycles. I don't have an isolated probe to show the...

I am using a Triac dimmer for dimming an LED (dimmable) lamp. The zero-cross detector is from a simple transistor on the secondary of the transformer (before smoothing). All works fine except that the LED flickers a bit in the low range. Analyzing on the scope the zero-cross pulses vary in the...

Thanks for your help m8. I have a similar one using IR led with a range of about 20m. I tried using a laser but focusing it was a headache and so used the IR LED. However this time I cannot use a reflector so am testing Ultrasonic.

I know the ground track runs a little around but adding the inductors and capacitors near the Pic should have solved the noise issue. Anyway I designed that some time ago and tried to use only 1 layer. I will change to smd now and add proper ground plane. But I still prefer to use a...

@Brian - Yes the Triac turn off was cousing some noise but the Pic was reset from external noise. It is driven with an opto already. @VE1BLL - I was testing with a small bulb about 25W - dont think a 7W would make much difference. @MacG - Actually I have another unit ordered and I need to add...

At the moment the unit is at the client cos he needed it so he took it as it is. I will re-design the pcb and test again and post back - maybe nest week. Thanks for all the tips suggested.

When I said the supply dropping I meant with noise and not due to not enough capacitance. I will design another PCB with more shielding and see if it works better. My last trick would be to save the state in eeprom and read it on reset but that's a little dirty :)

The circuit works fine until I switch some fluorescent lights or a driller. Even the motor of a freezer turning on/off was making the Pic to reset. I have captured the noise on the supply line with the scope which goes down to about 2V (ns) and so the BOR kicks in. I always leave the BOR turned...

I have disigned a dimmer circuit using Pic12F629. It works fine but with a little electrical noise the pic is resetting. I have added L1 and L2 inductors (see circuit) and some capacitors across the supply but did not solve it completely. Any idea how to make Pic completely immune to mains...

I am designing an H bridge using the FDMS7556S mosfet. The datasheet states - "This device has the added benefit of an efficient monolithic Shottky body diode." Does this mean that I can omit the catch diodes?

I've been looking for (cheap) outdoor ultrasonic sensors but could not find any assembled in a module (except Maxbotix which are out of budget). So I am thinking if changing the transducers on the SR04 module to waterproof type might work. Any feedback is welcome. My application is for a trip...

I need these for a fishing boat for powering an electric winch. It is not going to be submerged but should be IP67 at least. The Bucaneer 7000 series looks good and not too expensive. Thanks for the link.

I just bought this connector ***p://www.ebay.co.uk/itm/191278895319?tfrom=191405132575&tpos=unknow&ttype=price&talgo=origal It says 30A rated but on arrival I found the contacts to be only 1mm diameter which I really doubt they can handle 30A. So can someone point me to a similar connector...

I was seeing Discovery channel and they featured an electric motor bike that can stay standing by itself. This was a normal 2 wheel bike so I cannot figure out how it is possible to stay standing up by just actuating the motors. Any idea on the principle used?

Lol that was elementary :) Will get a resistor and have a try.

Thanks again. Infact schottky is rated at 30V 15A and uf diode is rated at 200V 16A and the price is comparable. But for 12V operation high current the schottky wins big time. Back to the motor flyback current. With the scope connected across the motor at 20kHz I have almost perfect square wave...

Nice idea benta. With schottky diode the forward drop goes below 0.5V while with the the other diode it was almost 1V. And viewing the waveforms there was no difference on the switching edges. So the question is - if schottky diode is better than the Ultra fast diode why do the latter exist? Or...

The diodes I am using are not cheap and I think I need 3 or 4 to minimize the heat. I may go for a heatsink with same price and better current handling. How much current passes through the flyback diode? If the motor takes 10A how much will the diode take back - continuous and pulsed? If I can...

I did some testing at 4kHz and 1kHz with no noticable improvement. I had to go down to 250Hz to get it working with no much heating at no load. However when loading motor the diode starts to heat again. Will have to test it at normal working load and see how it goes.