Comments on: The shocking power supplies https://www.epanorama.net/blog/2022/01/16/the-shocking-power-supplies/ All about electronics and circuit design Sun, 12 Apr 2026 21:37:09 +0000 hourly 1 http://wordpress.org/?v=3.9.14 By: Tomi Engdahl https://www.epanorama.net/blog/2022/01/16/the-shocking-power-supplies/comment-page-1/#comment-1871042 Tue, 17 Feb 2026 09:50:45 +0000 https://www.epanorama.net/blog/?p=190318#comment-1871042 Recommendation: If you need a 12V power supply for a hobby project, do not build this.
This is a Transformerless Power Supply (specifically a capacitive dropper circuit). While it looks simple and inexpensive, it is highly dangerous for most hobbyist applications. This circuit is not isolated from the mains. This is the most important thing to understand. Lethally dangerous to touch. When you first plug this circuit into a wall outlet, you encounter two major technical hurdles: Inrush Current and Zener Stress. Both of these factors make this specific design prone to premature failure (or a literal “pop”).

This type of design (not exactly this circuit as shown here) is typically found inside sealed consumer products like LED bulbs, cheap plug-in nightlights, or PIR sensors where the entire circuit is permanently enclosed in plastic and the user never touches the electronics.

]]> By: Tomi Engdahl https://www.epanorama.net/blog/2022/01/16/the-shocking-power-supplies/comment-page-1/#comment-1866235 Mon, 01 Dec 2025 12:06:41 +0000 https://www.epanorama.net/blog/?p=190318#comment-1866235 General warning on this type of circuits:
“This is dangerous” or other warnings for non isolated supplies. Many members make it clear if they see such a post.
The reason is that this group is public and many of them are beginners with little knowledge of electronics. Non isolated power supplies and SMPS are far more dangerous for beginners who might think 12v is safe to touch.

]]> By: Tomi Engdahl https://www.epanorama.net/blog/2022/01/16/the-shocking-power-supplies/comment-page-1/#comment-1850507 Fri, 04 Apr 2025 08:31:57 +0000 https://www.epanorama.net/blog/?p=190318#comment-1850507 That output current is dangerous, if you touch any of the DC points you will receive a shock, that circuit is not isolated

]]> By: Tomi Engdahl https://www.epanorama.net/blog/2022/01/16/the-shocking-power-supplies/comment-page-1/#comment-1848587 Sat, 15 Mar 2025 09:26:10 +0000 https://www.epanorama.net/blog/?p=190318#comment-1848587 https://hackaday.com/2025/02/24/line-power-with-no-transformer/

]]> By: Lessa https://www.epanorama.net/blog/2022/01/16/the-shocking-power-supplies/comment-page-1/#comment-1818649 Tue, 28 Nov 2023 21:34:34 +0000 https://www.epanorama.net/blog/?p=190318#comment-1818649 It’s good to see you talking about the upsides and downsides of transformer less power supplies. They’re becoming quite popular, especially in budget-friendly products.

]]> By: Lessa https://www.epanorama.net/blog/2022/01/16/the-shocking-power-supplies/comment-page-1/#comment-1818648 Tue, 28 Nov 2023 21:34:21 +0000 https://www.epanorama.net/blog/?p=190318#comment-1818648 It’s good to see you talking about the upsides and downsides of transformer less power supplies. They’re becoming quite popular, especially in budget-friendly products.

]]> By: Tomi Engdahl https://www.epanorama.net/blog/2022/01/16/the-shocking-power-supplies/comment-page-1/#comment-1817857 Mon, 20 Nov 2023 08:24:03 +0000 https://www.epanorama.net/blog/?p=190318#comment-1817857 https://hackaday.com/2023/09/29/power-supplies-without-transformers/

]]> By: capcutmod https://www.epanorama.net/blog/2022/01/16/the-shocking-power-supplies/comment-page-1/#comment-1817491 Thu, 16 Nov 2023 17:50:33 +0000 https://www.epanorama.net/blog/?p=190318#comment-1817491 ’m glad to see that you’re discussing the pros and cons of transformerless power supplies. They’re definitely becoming more common, especially in inexpensive products.

]]> By: https://capcuttemplatess.net/ https://www.epanorama.net/blog/2022/01/16/the-shocking-power-supplies/comment-page-1/#comment-1816556 Sat, 28 Oct 2023 15:57:37 +0000 https://www.epanorama.net/blog/?p=190318#comment-1816556 The shocking power supplies are a reminder of the importance of reliable CapCut Templates. Without them, unexpected power disruptions can lead to frustrating and costly consequences. Make sure to invest in quality templates to ensure a smooth and uninterrupted editing experience.

]]> By: capcutapk https://www.epanorama.net/blog/2022/01/16/the-shocking-power-supplies/comment-page-1/#comment-1814979 Wed, 04 Oct 2023 20:01:19 +0000 https://www.epanorama.net/blog/?p=190318#comment-1814979 I’m glad to see that you’re discussing the pros and cons of transformerless power supplies. They’re definitely becoming more common, especially in inexpensive products.

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