80's Playground 80's Playground

Electronics Mailbag / Postbag / Padded Envie Bonanza

  1. last year

    AC Slater

    23 Oct 2016 Administrator
    Edited last year by AC Slater

    I thought I'd start a different type of "latest pickup" thread around cheap electronics modules / boards and other parts. I have seen a few helpful youtube channels cover this type of stuff, so I thought a thread on the subject matter could be another way to look at them. Feel free to contribute your own finds here. Most stuff is from either Aliexpress, eBay, or Banggood, with lead-times of a few weeks.

    I'll start with this small this DC-DC converter. It is a kit you basically assemble some laser cut clear acrylic pieces around the board. It's a cute design as far as these boards go. It has a very nice backlight LCD display, which shows voltage and current, but is a little gimmicky since it shows a battery symbol with bars in it, but they don't really do anything. No on/of switch is to be found, however, the voltage can be calibrated for better accuracy.

    "DC-DC Step Down Power Supply Adjustable Module With LCD Display With Housing Case"

    Here is the unassembled kit:


    Assembled pic:


  2. AC Slater

    23 Oct 2016 Administrator
    Edited last year by AC Slater

    I had a pretty good run of not getting any wrong items until now. This kit was supposed to be a board that could play sound effects, but it is an LM386 kit, which actually could come in handy, but is not as interesting as what I had been waiting for. It even seems to come with an extra knob. Oh well, I made a new order and I'll post it here. I might try to build this and modify it for the extra bass config shown in the LM386 spec sheet.

    "LM386 Super MINI Amplifier Board DIY Kit Components and Parts"


  3. AC Slater

    23 Oct 2016 Administrator
    Edited last year by AC Slater

    A small kit of breadboard wires that are made with solid core wire. They come in handy for prototyping when you don't want wires flying everywhere.

    "140 pcs U Shape Solderless Breadboard Jumper Cable Wire Kit"


  4. AC Slater

    30 Oct 2016 Administrator

    A Raspberry Pi Zero with Wi-Fi dongle and camera attached.


    A No IR camera that's attached on the other end.


  5. AC Slater

    30 Oct 2016 Administrator

    Zero insertion force sockets. I got these to build a simple chip programmer.


  6. AC Slater

    30 Oct 2016 Administrator
    Edited last year by AC Slater

    A vibration alarm that works with a 9V battery. It is super loud!


    Internal shot:


  7. AC Slater

    30 Oct 2016 Administrator
    Edited last year by AC Slater

    Another DC-DC converter: DP30V5A-L by Hangzhou Ruideng Technologies. This one is a little on the higher end scale for these type of bare modules. The two displays are for voltage and current. The programmable voltage and current settings will save after power is cut from the unit and there is an on/off switch for the output. You can also switch to see the input voltage/current. Seems very accurate and the power up curve is smooth.


  8. AC Slater

    5 Nov 2016 Administrator
    Edited last year by AC Slater

    Yet another DC-DC converter. This one appears to be made by Drok since the back side has its logo. They sell a bunch of other ones like the one above on Amazon, but you can get them cheaper direct from their manufacturer or on eBay/Aliexpress. This one is similar to the one above, though setting the voltage and current is more annoying since you can't toggle to the decimal place to change the value so you have to press and hold (which easily overshoots) or keep clicking the button to get the value you want. It has a nice two color red/blue numerical display.

    "DROK® Numerical Control Voltage Regulator DC 5-32V to 0-30V 5A Buck Converter, 24V 12V to 5V Step Down Power Converter Adjustable Digital Control Voltage Reducer with LED Ammeter Voltmeter Display"


    Stock photo:


  9. Cool pics! It's interesting to see the difference in form-factor between the two similar DC-DC converters. The top board has such a beefy heatsink which makes me surprised to not see one on the MOSFET on the bottom board. The circuit design doesn't look any different which makes me think that that MOSFET would get very toasty.

  10. AC Slater

    6 Nov 2016 Administrator

    Thanks! Yeah, that's a good observation. The one without the heatsink says to add one over 2A, so they kind of cheaped out on the build. I guess the plus on that one is it's a little smaller if size matters. But the Ruideng one is the best value. The specs on a lot of these boards are probably exaggerated, but that one seems legit.

    Here's yet another DC-DC converter that just came in. I got this one to go into a project box to adjust the brightness of some LED floodlights for a project in the yard. Very beefy heatsinks on this one.

    DC-DC CC CV Buck Converter Step-down Power Supply Module 7-32V to 0.8-28V 12A



  11. AC Slater

    6 Nov 2016 Administrator
    Edited last year by AC Slater

    The replacement noisemaker (mentioned earlier) I ordered came here pretty quick. It will be a fun little kit to assemble. I wonder what it will sound like. It has one of those chip on board modules (the brown board with the epoxy blob) that I am guessing is an old analog design that can be messed around with. ;-)

    16 Music Box Sound Box Electronic Production DIY Parts Components Accessory Kits



  12. AC Slater

    6 Nov 2016 Administrator

    Not that exciting, but connectors make the electrons flow.

    Assortment of Dupont wires:


    2.5mm and 2mm JST connectors:


  13. AC Slater

    9 Nov 2016 Administrator
    Edited last year by AC Slater

    These didn't come in the mail, but are kinda related. These are Ikea LADDA AA and AAA rechargeable Ni-MH batteries that are the higher capacity ones (2450mAh and 900mAh). They are made in Japan and word is they come from the same factory that the famed eneloop batteries are made.



  14. AC Slater

    24 Nov 2016 Administrator
    Edited last year by AC Slater

    I got this uCurrent Gold multimeter adapter for measuring very small currents in some battery powered devices. It is made by a popular youtube vlogger Dave Jones, who seems to draw some controversy from his Aussieness. It turns out the measurements on my Fluke aren't that bad, but it's good to get confirmation. I think the industrial design could be improved with recessed plugs and switches. The switches are also a little fiddly to get into position. They seem to be made in smallish batches and sell out somewhat quickly, so you have to check on the bare bones web store.



  15. AC Slater

    24 Nov 2016 Administrator
    Edited last year by AC Slater

    I got a larger than usual mailbag this week, so I'll go over some of these in time. Most of this lot was from a shop called Robotdyn on Aliexpress.


    One I'll call out is a delightful buy since it was so cheap (less than $1 shipped) is this 2 relay unit to switch high voltages/currents. This one was not from Robotdyn, though they have these units also and in other configs, like single and more.


    I tested it in conjunction with this Robotdyn motion PIR sensor. That seemed to work ok with a 3V signal. Robotdyn has a bunch of cool boards but their documentation is non-existent. I asked for some details on this unit and they did not have any, which is disappointing.


  16. AC Slater

    12 Dec 2016 Administrator
    Edited last year by AC Slater

    Some SMD / surface mount adapter boards (SOIC-14 / TSSOP-14) for prototyping. Sometimes I just order some from OSH Park if I have nothing else to order from Adafruit. They are a good price, come fairly quick and sometimes come with jelly beans. The green boards came from China and took a long time to get here.




  17. andyandy

    14 Dec 2016 Moderator

    Those OSH Park boards look like a Jolly Rancher with the purple soldermask. Really neat looking!

  18. AC Slater

    19 Dec 2016 Administrator
    Edited last year by AC Slater

    Yeah, they are a cool combo with the purple and gold. But I wish they had black and gold boards were also an option.


    Another accumulation of packages. These were more boxy than usual, some things were repeats from before. I will focus on the DSO138 digital oscilloscope.

    It came in an interesting Styrofoam coffin, so I thought I'd take a pic of it.


    These often come as a kit, but I didn't want to assemble one since I have other stuff to work on, so I got it as an assembled unit. They can be found for less than $20, which is a pretty good deal. I plan on using it for simple stuff since the specs are limited.

    "DSO138 2.4" TFT Digital Oscilloscope 1Msps + Probe Analog Bandwidth (Welded)"



    Here is a kit for a clear case which was a pain to assemble. I will get some pics of the whole thing working in the next post.


  19. andyandy

    20 Dec 2016 Moderator

    I've gotten a few of those styrofoam shipping coffins where they use a whole roll of shipping tape to keep everything water tight. Anything to save a buck on shipping supplies. At least they used an ESD bag!

  20. AC Slater

    20 Dec 2016 Administrator
    Edited last year by AC Slater

    @andyandy Yeah, that's exactly how that brick was packaged. I guess it saves on weight compared to cardboard? Good point about the ESD bag, sometimes things like bare chips come in plastic baggies which is really annoying.

    Here's a pic of the fully assembled unit. I think it looks pretty neat. The display is nice-- I wish the measurement text could be disabled. Maybe it's an option, I haven't read the whole manual.


  21. Newer ›

or Sign Up to reply!