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bean zheng
bean zheng vor 5 Stunden
i have been using https://www.pcbgogo.com/?code=y for 3 years now, that has always worker out great.Mostly i have standard boards,so i can order some best
Summer Contest - Who is your favourite PCB order pooler?
Marcos Eduardo
Marcos Eduardo vor 20 Stunden
thanks for your patient... help me a recover a 1000W tie grid very similar to your circuit. 
Solar grid tie inverter re-engineered
TonGiesberts
TonGiesberts vor 1 Tag
From the main text: If the current drawn by the LT1021 (5 V version) is more than 2 mA the PNP transistor T1 supplies most of the extra needed current (UBE/R13). At a  voltage of 1.7 V across LED1 the current drawn by the LT1021 is about 5 mA. The red led (LED1) parallel to R13 limits the maximum current T1 can source, roughly 90…100 mA ((ULED1 – UBE)/R12). LED1 will light up if the current reaches its maximum (indicates current limiting active).   In normal operation the LT1021 is never overloaded! In case there’s 1.7 volts across T1 and R12 there’s something seriously wrong with the circuit. Maximum current consumption of the whole circuit (K1) is specified as 50 mA max. This also includes current drawn by MOD2! So all components operate well within their safe limits.  
Potential-free current measurement for oscilloscopes [150170]
F1Andy
F1Andy vor 1 Tag
Thanks Paul, Amazing - I didn't see that when I made the video!   It is normally ticking with consistent 1 second ticks (with around 10mS jitter as far as I can tell). This happens if you don't send the commands to the GPS module at start up - the timing of the GPRS string jumps about, but is always within a 1 second window - and it looks horrible! The commands that are sent to the GPS module tell it to stop transmitting 4 other NMEA strings, so that the GPRS string is the only one being sent.  Consequently its timing is very consistent. At switch on, the software waits for the RX line from the GPS module to go high, before sending those strings.  I suspect that switching off, then straight back on again to make the video caused the strings to be sent to the GPS before it was ready; so they were not turned off.... I'll test this theory, and if needed, post a fix - likely as simple as allowing a short delay before sending the strings to the GPS module.  However, if I am correct, just switching off, waiting a few seconds, and then switching back on again will correct this.  (I am away from home this week, so it will be at the weekend before I get to it unfortunately.) For the PPS, I will use the JP1 link input, as that is no longer used.  I plan to auto-detect the PPS, so that if it stops (or the hardware modification hasn't been made), the clock reverts to updateing when the GPRS string arrives, as per the original. This would mean that the software can be loaded without any modifications apart from changing to a push-button switch; and hardware changes made as desired to enable extra features. Andy  
6-digit Nixie clock [150189]
ZOLTAN MIKLOS
ZOLTAN MIKLOS vor 1 Tag
Hi Anders, I have searched the internet for two days for the Murata CSB517 resonator, but I can't find a source. Nothing at Mouser, Digikey, Farnell, RS, etc. Can you tell me where did you get it? Thanks, HA5OZ
Navtex receiver