As mentioned in the previous video this month will be mostly InTheMail episodes because I just have a bunch of stuff from China and I gotta show it to you before I go use it on other projects. Same as before I tried grouping similar items in this episode so let’s get started on another InTheMail.
Here is a list with all the items shown in this video:
Bourns 10K 10 Turn Potentiometer
Plastic Rotary Knob 6mm Shaft 10pcs
16mm Potentiometer Knob Black With 6mm Shaft
3P4T 3 Pole 4 Position Rotary Selection Switch
On/Off Momentary Push Switches
PBS-11A Locking 2 Pin On/Off Switch
KSD9700 Slim Bimetal Temperature Switch
KSD301 Bimetal Temperature Switch
2mm Binding Post Plug Connectors
M5 Banana Jack 4mm Socket
3.5mm Slim Metallic Stereo Jack 4 Pole
JST XH 2.5mm Connector With Wire Set
1007 Hook Up Wire 24AWG
Links to all of these products are in the video description visible on youtube.
Welcome to a new InTheMail, the series that everybody seems to like, seriously I’m thinking this is starting to look like some group meeting where we all have the addiction to keep purchasing cheap electronic stuff from China.
Here is a list with the items shown in this video:
SG3525A PWM generator module
Photocell Automatic On/Off Light Switch Relay
B0505S-1W Isolated 5V DC-DC Converter
5V 2A DC-DC Converter USB Charger With Voltmeter Module
5V 3A DC-DC Converter USB Charger Module
12V 0.5A AC-DC Switching Power Supply Module
LCD1602 I2C Serial Interface Adapter Module
WS2812 RGB LED Controller
WS2812 RGB LED Strip PCB Module
You can find links to all of these items in the video description visible on youtube.
This is the first AC-DC power supply that I’m designing and building. Everything seems to work up to a point where the chip (TNY 276 from Power Integration) gets too hot and enters thermal protection. This is where I’m asking my viewers help to jump in with suggestions on what might be wrong.
This is part 2 where I get the circuit working by switching from the TNY276 to the TNY277 which has a higher power rating and is probably the proper IC to use with this transformer (EE1616 ER2741)
And this is part 3 of the video where I finally find the real fault in the circuit. It turns out I was right, this circuit should have worked with the TNY276 as well and it wasn’t the higher power rating of the TNY277 that fixed the issue.
A while ago I saw this touch musical keyboard kit on banggood and it seemed interesting enough to order one. It turns out the kit is using a single atmega8 to do all the touch sensing (8 ch) and play the tunes accordingly. Although not very useful for me it sure was fun to assemble and play with.
Sometimes, when I have some spare time I like assembling these cheap kits coming from China. Today I am assembling an LM317 adjustable power supply kit complete with voltmeter. Unfortunately they sent me a wrong resistor value so the kit didn’t work as expected but I was able to fix it in the end.
A while ago I watched a video from Scullcom Hobby Electronics channel where he build a precision current source, a very simple but accurate one. If you don’t know this channel I encourage you to subscribe to it, it has allot of nice videos on lab equipment either building DIY versions or reviewing existing ones. Each video has nice drawings and the guy clearly knows what he is talking about so a great resource for learning.
I don’t have any current source in my lab, and these are useful for testing multimeters for example. I was looking on ebay for a current source but I wasn’t able to find an affordable one so I’ve decided to build one using the project information from that video and I will link the video in the description below, it’s nice to watch it has lots of interesting explanations so I won’t repeat them in this video, I will mostly focus on showing you how I build and improved my current source.
If you were following my InTheMail videos you probably seen these green rechargeable batteries that I got from ebay quite cheap, I think they were like 50 cents a piece. I got 4 pcs in AA size and 4 pieces in AAA size and little did I know about how crappy these could be.