What Voltage is my eGo Running at?

[Rocketman]

The twist and Provari might use PWM deep inside but it gets filtered before it gets to the connector so it looks like a smooth DC voltage. A small amount of the high frequency and some error amplifier signal component can be seem on the output, but mostly DC out. The PWM in the switching circuit really only comes into play when under light load. The current pulses through the inductor are 100's of times faster than the frequency of the eGo and the output capacitor filters that into DC.

The ego uses a low enough PWM frequency (under 100 Hz) that the in-line meter sees the 0V periods as 0V, shuts down and starts over, over and over. Never gets to make a measurement cycle. The meter sucks power to power itself. If power shuts off (the 0 volt period), it performs a Power-On-Selftest and tries to start a new measurement cycle .

 

[DaveP]

One day, I will find a cheap deal on a modern day o-scope and jump.

I used to have access to a Tektronics scope at work before I retired. We had to have it to set up digital tape ramp voltages and adjust read heads on platter type disc drives in the old days before miniature backups and network storage made them obsolete. I don't know if you remember them, but the Centronics removable multi-platter flying head drives used to use a disc pack that looked like a science fiction movie space station! They sucked air through a 100 micron filter to prevent head crashes.

FWIW ... notice that this only held 100mb. There was a 300mb high density model. Whoo-hoo!

 

[Rocketman]

That's 'modern' stuff.
I worked with a 20 bit airborne ballistic/navigation computer that had a 75KB Drum memory, and a 128KB scratch pad core memory. No IC's, but over 3000 2n293 transistors. Could run game like simulations with a bombing solution every microsecond. (faster than most games now).

A cheap scope would be a handy addition to the 'Home Lab'. Just takes a watchfull eye for a bargain.

 

[Photon55]

Excellent explaination of pulse modulation involving duty cycle.