F/5.6, 1/60, ISO 200.
Day 308 / 365
Experiencing problems with his computer, an incognizant user called technical support for assistance …
Technician: Good morning. How may I help you?
Customer: There’s smoke coming from my computer’s power supply.
Technician: Sounds like you need a new power supply.
Customer: No, I don’t! I just need to change the startup files.
Technician: Sir, what you described is a faulty power supply. It needs to be replaced.
Customer: No way! Someone told me that I just have to change the system startup files to fix the problem! All I need is for you to tell me the right command.
For the next several minutes, despite the technician’s efforts to explain the problem and its solution, the customer adamantly insisted that he was right. So, in frustration, the technician responded …
Technician: I’m sorry. Normally we don’t tell our customers this, but there is an undocumented DOS command that will fix the problem.
Customer: Aha! I knew it!
Technician: Add the line ‘LOAD NOSMOKE.COM’ at the end of the CONFIG.SYS file and everything should work fine. Let me know how it goes.
A few minutes later, the technician received a call back from the customer …
Customer: It didn’t work. The power supply is still smoking.
Technician: What version of DOS are you using?
Customer: MS-DOS 6.22.
Technician: Well, that’s your problem. That version of DOS doesn’t include NOSMOKE. You’ll need to contact Microsoft and ask them for a patch. Let me know how it all works out.
An hour passed and the technician received another call from the customer …
Customer: I need a new power supply.
Technician: Really? How did you reach that conclusion?
Customer: Well, I called Microsoft and told the technician what you said, and he started asking me questions about the make of the power supply.
Technician: I see. What did he tell you?
Customer: He said my power supply isn’t compatible with NOSMOKE!
Interesting Fact: 1910 An inductive discharge ignition system invented by Charles F. Kettering and his company (Delco) goes into production for Cadillac. This is a mechanically-switched version of a flyback boost converter with an autotransformer (the ignition coil). Variations of this ignition system are in all non-diesel internal combustion engines. 1926 “Electrical Condensors” by Coursey mentions high frequency welding and furnaces. 1936 Car radios used electromechanical vibrators to transform the 6 V battery supply to a suitable B+ voltage for the vacuum tubes. 1959 Transistor oscillation and rectifying converter power supply system U.S. Patent 3,040,271 is filed. 1970 High-Efficiency Power Supply produced from about 1970 to 1995. 1972 HP-35, Hewlett-Packard’s first pocket calculator, is introduced with transistor switching power supply for light-emitting diodes, clocks, timing, ROM, and registers. 1977 Apple II is designed with a switching mode power supply. “Rod Holt was brought in as product engineer and there were several flaws in Apple II that were never publicized. One thing Holt has to his credit is that he created the switching power supply that allowed us to do a very lightweight computer“. 1980 The HP8662A 10 kHz – 1.28 GHz synthesized signal generator went with a switched power supply. ( https://en.wikipedia.org/wiki/Switched-mode_power_supply#History )