02-12-2016, 02:42 PM
It will be an SMPS inside - some kind of switching oscillator, a step up choke or transformer and rectifier/smoothing for the output.
Here's an example (although whether the LT1615 was around 30 years ago, I don't know!)
![[Image: Step-up-DC-DC-Converter.png?w=480]](http://i0.wp.com/powersupply33.com/wp-content/uploads/2011/07/Step-up-DC-DC-Converter.png?w=480)
It will work quite happily with a 1.5V input and the value of R2 sets the output voltage - 111kΩ for 15V, using the formula shown and 1.5V input.
Reducing the input to the normal voltage of a dry cell - 1.4V - will produce an output of 15.4V with R2 = 100kΩ.
Here's an example (although whether the LT1615 was around 30 years ago, I don't know!)
It will work quite happily with a 1.5V input and the value of R2 sets the output voltage - 111kΩ for 15V, using the formula shown and 1.5V input.
Reducing the input to the normal voltage of a dry cell - 1.4V - will produce an output of 15.4V with R2 = 100kΩ.
