Is this a correct connection of the 22nf cap?
I tested 22nf it and it's bright a little less than a pcb with a MCP101-475HI/TO.
So with the MCP101-475 it's a little brighte! Why it so?
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I don't understand the question. The purpose of replacing the MCP101 with the cap is to minimize the bright flash at power on (reset time). This should be much shorter with the cap than with the MCP101.
The brightness after the reset period should be the same with the cap or the MCP101.
The cap is in the correct position.
A reset controller like the MCP101 provides a well defined reset pulse at power on. It also monitors Vcc and provides a reset pulse if the voltage sags below the threshold level. If you use a cap for reset, you will get a reset pulse at power on, but it does not provide "brown out" protection if the voltage sags or abruptly drops, such as in a vehicular (or other electrically noisy) application. Without that protection, the uP can lock up or do erratic things.
For an application like this strobe, a cap is more than adequate and by using a smaller value (but not too small, the reset pulse must be a certain number of clock cycles to work), the reset time can be shortened.
I built this in a hurry and looking back, could have done the output with opposite polarity (active low) that would have prevented the bright flash at power up (the uP pins are high by default during reset).
The beauty of Xeon tubes was that they produced a very bright, very short pulse of light. These LED strobes are ~square wave driven, ie on 50% of the time so you get a blur. My suggestion is to charge a cap and discharge it into the LED, abusing their normal current rating. If you just reduce the duty cycle then you don't get much light. So make a push-pull output and AC couple it to a LED(s) and a reverse diode. Try different cap sizes for the best brightness-pulse width trade-off. Note that anything faster than 25Hz is probably a waste due to the limits of human vision, which could improve the trade-off.
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Not if the input voltage drops below the input threshold of the regulator. With a battery and a switch, the input voltage could switch between B+ and zero rapidly as the switch contacts bounce.
The reset pulse width of the MCP101 is fixed internally. The only way to fix it using the MCP101 is to redo the firmware and hardware to make the output active low.
The duty cycle of the pulse is 1/16 (525uS on time @ 120Hz) so it will not blur the line on a strobe disk (or only minimally). The resistor values are already designed to run the LED(s) at higher than "normal" current. Running them at any higher current than that will not increase the brightness proportionately, only lower the MTBF. There are also pads for up to 3 LEDs which should provide plenty of brightness.
Is it hard to do a version 1.01 of the firmwire?
The task is to write a new code and to reprogramm AT89C2051?
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