projects:tek222bat
Differences
This shows you the differences between two versions of the page.
| Both sides previous revision Previous revision Next revision | Previous revision | ||
|
projects:tek222bat [2016-06-12 15:42] robert [Circuit and Board Layout] |
projects:tek222bat [2020-05-31 11:32] (current) robert [Tektronix 222 Battery Pack] |
||
|---|---|---|---|
| Line 1: | Line 1: | ||
| ===== Tektronix 222 Battery Pack ===== | ===== Tektronix 222 Battery Pack ===== | ||
| - | For those of you interested in a multimedia audio-visual experience, there is a little overview video of the battery pack of youtube [[https://youtu.be/LJ2VS3aohV0|here]]. | + | For those of you interested in a multimedia audio-visual experience, there is a little overview video of the battery pack on youtube [[https://youtu.be/LJ2VS3aohV0|here]]. |
| + | |||
| + | If you would like to buy a ready-made replacement battery unit based on this design, N0DY Electronics is building and selling them [[https://www.n0dy.com/product/tekcharger/|here]]. | ||
| ==== Introduction ==== | ==== Introduction ==== | ||
| Line 33: | Line 35: | ||
| ==== Overview ==== | ==== Overview ==== | ||
| - | Starting out, I new that I had to (or wanted to) build a circuit that wraps around one or more lithium cells and makes them behave like the original 8V SLA battery as far as the scope is concerned. The way I chose to achieve this is shown in the following diagram: | + | Starting out, I knew that I had to (or wanted to) build a circuit that wraps around one or more lithium cells and makes them behave like the original 8V SLA battery as far as the scope is concerned. The way I chose to achieve this is shown in the following diagram: |
| {{ :projects:scope-bat.png?direct&400 |}} | {{ :projects:scope-bat.png?direct&400 |}} | ||
| Line 104: | Line 106: | ||
| You can download the design files from here: | You can download the design files from here: | ||
| - | * Schematic PDF {{:projects:scope-bat-sch0.pdf?linkonly}} | + | * Schematic PDF {{:projects:scope-bat1.pdf?linkonly}} |
| - | * Bill of Materials {{:projects:scope-bat-bom.csv?linkonly}} | + | * Bill of Materials {{:projects:scope-bat1.csv?linkonly}} |
| - | * PCB Gerbers {{:projects:scope-bat-gerbers0.zip?linkonly}} | + | * PCB Gerbers {{:projects:scope-bat1.zip?linkonly}} |
| - | * Schematic and PCB layout (DipTrace 2.9) {{:projects:scope-bat-design0.zip?linkonly}} | + | * Schematic and PCB layout (DipTrace 3.1) {{:projects:scope-bat1-design.zip?linkonly}} |
| + | * DXF files for acrylic case parts {{:projects:bat-acrylic.dxf?linkonly}} | ||
| - | **IMPORTANT:** This schematic reflects the board design, and does not incorporate the required bodges. If you just build the circuit from this schematic, it will not work. Please see the updated schematic below for a circuit that incorporates the changes: | + | The above files are for Revision 1 of the board, which has been built a number of times and proved to be robust. |
| - | * Schematic PDF {{:projects:scope-bat-sch0.pdf?linkonly}} | + | |
| - | + | ||
| - | If you decide to build the circuit from the revision 0 board / schematic, you need to apply the following fixes: | + | |
| - | * Add a 1MΩ pull-up resistor on OUTA (pin 1) to Vs (pin 5) of the LT6700. | + | |
| - | * Add a 4.7µF ceramic capacitor in parallel with the decoupling capacitor of the LT6700. | + | |
| - | * Add a 10MΩ feedback resistor between OUTA (pin 1) and INA, INB (pins 3 and 4) of the LT6700. This increases the hysteresis voltage. (optional) | + | |
| - | * Add a 1µF ceramic capacitor in parallel with each of the electrolytic capacitors. | + | |
| - | + | ||
| - | There are a few other changes that I'd like to make to the PCB (mainly ground plane layout), but I think it's unlikely that I'll ever do another run. | + | |
| {{ :projects:bat-switcher-top.jpg?direct&400 |}} | {{ :projects:bat-switcher-top.jpg?direct&400 |}} | ||
| Line 161: | Line 155: | ||
| The datasheet does mention that the reference is sensitive to noise, but I didn't expect it to have that kind of effect. Adding a 4.7μF decoupling cap on the comparator in parallel to the existing 100nF solved that issue. If I were to re-spin the board, I'd probably add an RC filter on the supply line, just to be on the safe side. | The datasheet does mention that the reference is sensitive to noise, but I didn't expect it to have that kind of effect. Adding a 4.7μF decoupling cap on the comparator in parallel to the existing 100nF solved that issue. If I were to re-spin the board, I'd probably add an RC filter on the supply line, just to be on the safe side. | ||
| - | |||
| - | ==== Free Boards! ==== | ||
| - | Thanks to obtaining [[http://dirtypcbs.com/|dirt cheap PCBs]] from China, I have quite a few bare boards spare which I'm probably never going to use. If you'd like to build your own board, please just contact me and I'll send you one for the cost of postage. | ||
projects/tek222bat.1465756973.txt.gz · Last modified: 2016-06-12 15:42 by robert
Page Tools
