A brief follow-up to Organizing electronic components, in this article I’ll improve the organization of my electrolytic capacitors, and add to the stockpile by salvaging from an old DVD player circuit board (which I already salvaged the VFD from, in the previous blog post Reverse-engineering the pinout of vacuum-fluorescent displays (VFDs): HNV11SS27, FIP7FM7, and HNV-08SS53).
While I had extensively and neatly organized resistors, the capacitor organization is wanting. Lacking space, I reluctantly sorted the capacitors into several large buckets, grouped together by vast ranges of capacitance:
For the electrolytics (on the far left), I used:
- ≥100 µF
- ≤100 µF, further subdivided into: ≤33 µF, and ≥47 µF ≤ 100 µF
Better than nothing, but in practice it was too cumbersome to find the correct capacitor value I wanted, laboriously searching through each tray. Fortunately I was able to acquire another organizer, with dividers allowing either 18 or 12spaces. I went with 12, since there are usually fewer common values for electrolytic capacitors, and began to sort out what I had on hand:
- 0.1 µF (2)
- 0.47 µF (1)
- 1 µF (0)
- 4.7 µF (3)
- 10 µF (many)
- 22 µF (6)
- 33 µF (2)
- 47 µF (10)
- 100 µF (6)
- 220 µF (1)
- 470 µF (8)
- 1000 µF (4)
- 1 F (6)
The 1 farad is a Nichicon JUWT1105MCD supercapacitor ordered from Digi-Key, previously briefly discussed in Voltage regulators revisted: LM317M, 7812, MCP170x, MIC5219, and ICL7660. Not something I’ll expect to salvage going forward, so I grouped 1 F together with 1000 µF in “≥ 1000 µF”. Secondly I had several 1 µF and expect to acquire more, so I saved it a slot. Altogether these are 12 values, a perfect fit for the 12-slot organizer:
Salvaging more electrolytics
Although electrolytic capacitors can be purchased inexpensively, they are easy to salvage from discarded circuit boards. This Samsung DVD player is particularly rich in electrolytics:
After unsoldering all ~90 electrolytic capacitors on this board:
The components unsoldered effortless, no solder wick required, merely heating up one of the leads, pulling the capacitor out from the other side, then repeating for the second lead. All but one (82 µF 400 V) fit into my organizational scheme, replenishing the supply:
Salvaging other components
While I was at it, I desoldered a handful of other components. Not too many for now, since the vast majority are surface-mount, but here’s the small haul:
including four NPN transistors with an ECB pinout, one PNP transistor with an ECB pinout (neither shown), some power resistors (2.7 Ω, 2 x 27 kΩ), a 1.0 A 250 V fuse, MOVs, a diode in a TO-220 package with a heatsink, 22 nF ceramic capacitor (223) (notably, this value was not present in the 300pcs 30value ceramic capacitor kit I had ordered, included 222 and 332 but no 223), and miscellaneous other parts.
Salvaging the remaining components will have to wait for another time:
Repurposing the component drawers
Having moved the electrolytics to their own plastic box, I freed up two drawers in the small parts cabinet seen in Organizing electronic components. What to do with this extra storage space?
Subject to change, but for now I settled on: fuses (3, including one from this DVD player board), and assorted ICs (including a TL431 shunt regulator, have encountered before in Voltage regulators revisted: M317M, 7812, MCP170x, MIC5219, and ICL7660: TL431 shunt regulator as current limiter and Exploring ternary logic: building ternary inverters using complementary MOSFETs).
Conclusions
In this short follow-up to Organizing electronic components, we have seen a simple organization scheme for storing salvaged electrolytic capacitors.