Recent content by mjhilger

Let me first state that these next few words are my opinion on a design philosophy to maximize power from a solar cell. The design request is to operate a solar cell using MPP to charge a battery pack. I view this a an advanced circuit. The reason I state this is that in order to actually...

I would suggest that you look into creating a system that determines the MPP dynamically at run time. I say this because many variables factor into the point that change your cells output characteristics, dirt on the glass, outside temp, angle, haze, etc. Since you want to charge 3.7 volt cell...

Post a schematic. At the moment we don't have enough info to analyze your issue.

If I understand correctly, your trouble seems to be the fact that the ε2 source is not represented in the first equation. The issue is that I2 is not a part of the loop equations in their most basic form. Rather I2 = I1 - I3, and there are only two equations that are necessary for the drawn...

I would also point out that while on a microcontroller level, Microchip or other manufacturers single chip solution is a fantastic platform (I personally love Microchip and all their support available on the site in the form of app notes and app specific code.); if this is just for your...

There are certainly adapters that would allow two male stereo inputs to one female output. However I don't consider it good practice to tie two power outputs together without some isolation circuit. The OP used resistors, and says it it has some crossover issues. A small headphone summing amp or...

I think the OP wants to go the other way. Combine 2 source signals to one headphone. He has taken a passive approach in using resistors. Not sure based on the way it is worded as to whether the resistors are set as load or in series with the source to drive to the phones. Ultimate solution...

I would say that the book design is such to keep the loading on inverted and non-inverted signals equal. Also if you look at the book solution, the output is virtually identical for each pin. This could also be to keep the propagation times equal in all outputs. There are numerous ways to...

YES! Big problem without resistors! The base to emitter junction is a forward bias PN junction when "on". As such that voltage is around 0.7 volts. Since your base of the ground path transistor is tied to the base of the +V side transistor they will both be approximately 0.7 above ground when...

The difference is the path to ground. In the first figure, the design uses npn transistors, and in the second it uses pnp transistor to pull to ground. With bipolar transistors you will probably see using either of these designs, more heat generated in the transistors than if you used a design...

I would say if you are truly interested in learning the engineering side to the extent of understanding the why a circuit works, you need to start with the basics of Electrical Engineering. You should find the book used in an intro to Electrical Engineering so you might begin to understand how...

Then almost certainly Li-Po. If it is reading 4.7, then it is probably already damaged and if it holds a charge will not preform anywhere near its original ratings. Li-Po charging is complex compared to NimH or NiCd; Li-Po ideally requires constant current until a cell reaches 4.205...

The attached photo looks to me as a Li-Po; is that all aluminum around the pack? If so almost definitely Li-Po. If it looks like only one item, then it is a single cell, max voltage after charge should be 4.205 volts. If it has a higher charge, it has probably been damaged. Please KNOW...

PIC, ATMEL, LATTICE, etc. manufacturers as well as any FPGA (and all ARM based) that can contain a microcontroller, will all have a version of C or C++ available to program. Many will have API's that help program different peripheral parts of their specific chips. Industry jobs that utilize...

My personal opinion: Arduino is a hobby module that has a lot of support and built in functions which allows you to utilize a microcontroller to control devices connected to the board. However, if you want to LEARN about programming a microcontroller, my choice would be a PIC from...