Hi everyone,
Just wanted to check if anyone has built the DEFX Charonium -> https://drive.google.com/file/d/1Q3IoVusmR10JOCUQlSS9JIMDiEl62xII/view (https://drive.google.com/file/d/1Q3IoVusmR10JOCUQlSS9JIMDiEl62xII/view). I am sourcing parts at the moment and I am wondering about a couple of parts:
- 460 ohm resistor: can it be replaced by a 470 ohm resistor?
- 7v zener diode: does it have to be exactly 7v or can it be 6.8v or 7.1v?
Kind regards,
Martijn
Quote from: spacekid71 on February 17, 2021, 09:45:13 AM
Hi everyone,
Just wanted to check if anyone has built the DEFX Charonium -> https://drive.google.com/file/d/1Q3IoVusmR10JOCUQlSS9JIMDiEl62xII/view (https://drive.google.com/file/d/1Q3IoVusmR10JOCUQlSS9JIMDiEl62xII/view). I am sourcing parts at the moment and I am wondering about a couple of parts:
- 460 ohm resistor: can it be replaced by a 470 ohm resistor?
- 7v zener diode: does it have to be exactly 7v or can it be 6.8v or 7.1v?
Kind regards,
Martijn
You don't need that diode at all, and you can use 470 ohm resistor instead of 460.
Hi Rankot,
Ah okay that is good to know. In general when a circuit calls for a 7V zener, can I take a 1n4736 (6.8 volt) or a 1N4737 (7.5 volt) ?
Thanks,
Martijn
Quote from: spacekid71 on February 17, 2021, 11:48:49 AM
Hi Rankot,
Ah okay that is good to know. In general when a circuit calls for a 7V zener, can I take a 1n4736 (6.8 volt) or a 1N4737 (7.5 volt) ?
Thanks,
Martijn
Check datasheets and schematics, it can not be said as a rule of thumb. But have in mind that all the parts have a tolerance, so both of those values are within 10%, which is almost always acceptable.
What Ranko said.. :icon_wink:
460R (470R) forms power supply Low Pass Filter (togheter with C2) and fed circuit could live with a 2% additional voltage drop..
(it also limits C2 inrush current when start-up but it's a minor benefit here..)
As for Zener, its precise breakdown voltage is mostly depended on indicator LED (D3) forward voltage drop (+9V - VZener - VD3 - [ILED x 4k7] = 0)