it doesn't. it only works incidentally. The author isn't an EE and has designed a circuit as if an artist (or an AI) drew a picture of what a circuit looks like.
The weird topology voltage divider attenuates the signal. the op-amps buffer the output. The 470R resistors do nothing. The 1k/1k virtual ground does nothing.
The rest of the authors writings smell of /r/iamverysmart
once, when complaining to a colleague about our workplace and their hiring and staffing idiosyncrasies, I quipped "I should give <manager> a copy of TMMM". My colleague, without missing a beat said "You should give him two copies so he can read it faster"
I thought about making one of these - actually I designed it, but never made the PCB for it - because the internet is full of similar ones:
https://www.ebay.com.au/itm/195143066807
There are a few dynamic pricing energy retailers in Australia too. It often goes negative, sometimes for many hours at a time. Usually it’s hard to make money off it because it’s often at times of the year and day that there is no need for heat/cooling.
it's actually persisted more recently. I just checked a High Sierra machine. "Messages" has an "Add Jabber Account" menu option. An it's recent enough that it plays nice with all my existing more modern iPhone/macOS etc iCloud messages.
In the slightly olden days, iMessage - or whatever it was called then - had a built in jabber client, and there was brief period (Sierra era?) that iMessage/iCloud could sync up all your messages across google and apple and SMS.
I _think_ it would have enabled this functionality, if anyone knew and/or investigated it.
I have once of his Klein bottles. It came in the most amazing personally decorated package that I've kept that too, and value it almost as highly as the glassware.
I have a HP laserjet 6L from 1993. It still works, although the paper feed needs to be encouraged sometimes. Doesn't get a lot of use anymore, but I think we only ever bought one new toner cartridge for it.
Sometimes you can get away with just guessing pull-ups, but sometimes you need to calculate them. Drive strength, speed, line capacitance, line length, number of devices, supply voltage, threshold levels... it's all stuff you take into account when designing for I2C properly.
Reading the datasheets for both devices would probably avoid the problem.
yes. it comes up green, but is delivered to all other same account iCloud devices. you can reply too, and it works it out. I send and receive SMSs via my MacBook and iPad.
the phone in a drawer solution works basically by default on apple devices. Very common solution in outback Australia (satellite internet only, no phone coverage)
I agree, it makes no sense. I am a real hardware electronics engineer and I don't understand his explanation. I believe the LDO could fail in a temperature dependent way. I do not believe the explanation.