George said he needed a problem to think about.... here's a bit of a change from your usual design projects. What's the simplest useful electronic product you can think of? Excluded are small amplifiers & oscillators, those have been done. Heating items such as kettles are excluded as they won't be very useful in this situation. Reaction radios are out due to legal issues. By useful I mean in areas of the developing world where electricity is available to a percentage of users. The item must be makeable entirely from parts from scrap, your digikey budget is zero. So no uncommon components. It could be a domestic item, business item, manufacturing tool, anything of use. NT
Simple useful appliance?
Started by ●February 7, 2018
Reply by ●February 7, 20182018-02-07
On Wednesday, February 7, 2018 at 8:04:02 AM UTC-5, tabb...@gmail.com wrote:> George said he needed a problem to think about.... here's a bit of a change from your usual design projects. > > What's the simplest useful electronic product you can think of? Excluded are small amplifiers & oscillators, those have been done. Heating items such as kettles are excluded as they won't be very useful in this situation. Reaction radios are out due to legal issues. > > By useful I mean in areas of the developing world where electricity is available to a percentage of users. The item must be makeable entirely from parts from scrap, your digikey budget is zero. So no uncommon components. > > It could be a domestic item, business item, manufacturing tool, anything of use. > > > NTHmm I heard somewhere that your best bang for buck in the third world is mosquito netting, to reduce malaria. An electronic mosquito killer? George H.
Reply by ●February 7, 20182018-02-07
On Wed, 07 Feb 2018 05:03:57 -0800, tabbypurr wrote:> George said he needed a problem to think about.... here's a bit of a > change from your usual design projects. > > What's the simplest useful electronic product you can think of? Excluded > are small amplifiers & oscillators, those have been done. Heating items > such as kettles are excluded as they won't be very useful in this > situation. Reaction radios are out due to legal issues. > > By useful I mean in areas of the developing world where electricity is > available to a percentage of users. The item must be makeable entirely > from parts from scrap, your digikey budget is zero. So no uncommon > components. > > It could be a domestic item, business item, manufacturing tool, anything > of use. > > > NTHow about those AC outlet testers- a plug with indicators. I once made a DC polarity indicator for a guy, so he wouldn't blow his VHF radio moving it from boat to boat.
Reply by ●February 7, 20182018-02-07
On Wednesday, 7 February 2018 16:02:26 UTC, Wond wrote:> On Wed, 07 Feb 2018 05:03:57 -0800, tabbypurr wrote:> > George said he needed a problem to think about.... here's a bit of a > > change from your usual design projects. > > > > What's the simplest useful electronic product you can think of? Excluded > > are small amplifiers & oscillators, those have been done. Heating items > > such as kettles are excluded as they won't be very useful in this > > situation. Reaction radios are out due to legal issues. > > > > By useful I mean in areas of the developing world where electricity is > > available to a percentage of users. The item must be makeable entirely > > from parts from scrap, your digikey budget is zero. So no uncommon > > components. > > > > It could be a domestic item, business item, manufacturing tool, anything > > of use. > > > > > > NT > > How about those AC outlet testers- a plug with indicators. > I once made a DC polarity indicator for a guy, so he wouldn't blow his > VHF radio moving it from boat to boat.Yes - that's been done too though. NT
Reply by ●February 7, 20182018-02-07
On Wednesday, 7 February 2018 16:02:26 UTC, Wond wrote:> On Wed, 07 Feb 2018 05:03:57 -0800, tabbypurr wrote:> > George said he needed a problem to think about.... here's a bit of a > > change from your usual design projects. > > > > What's the simplest useful electronic product you can think of? Excluded > > are small amplifiers & oscillators, those have been done. Heating items > > such as kettles are excluded as they won't be very useful in this > > situation. Reaction radios are out due to legal issues. > > > > By useful I mean in areas of the developing world where electricity is > > available to a percentage of users. The item must be makeable entirely > > from parts from scrap, your digikey budget is zero. So no uncommon > > components. > > > > It could be a domestic item, business item, manufacturing tool, anything > > of use. > > > > > > NT > > How about those AC outlet testers- a plug with indicators. > I once made a DC polarity indicator for a guy, so he wouldn't blow his > VHF radio moving it from boat to boat.Yes - that's been done too though. NT ============================================ Did they include frequency so they could verify proper generator rpm? What do you mean by a "reaction" radio? -- Regards, Carl Ijames
Reply by ●February 7, 20182018-02-07
On Wed, 7 Feb 2018 05:03:57 -0800 (PST), tabbypurr@gmail.com wrote:>George said he needed a problem to think about.... here's >a bit of a change from your usual design projects. > >What's the simplest useful electronic product you can think >of? Excluded are small amplifiers & oscillators, those have >been done. Heating items such as kettles are excluded as >they won't be very useful in this situation. Reaction radios >are out due to legal issues. > >By useful I mean in areas of the developing world where >electricity is available to a percentage of users. The item >must be makeable entirely from parts from scrap, your >digikey budget is zero. So no uncommon components. > >It could be a domestic item, business item, manufacturing >tool, anything of use. > >NTDeveloping world? A fairly high percentage of people in Africa have cell phones or smartphones (to discourage POTS line copper theft): <http://www.pewglobal.org/2015/04/15/cell-phones-in-africa-communication-lifeline/> <https://www.huffingtonpost.com/2015/04/20/africa-phone-study_n_7081868.html> It's much the same in other parts of the developing world. Methinks one can safely assume that electricity is available in some form to charge these phones. Presumably, they also have all the gadgets needed to operate a cell phone, such as a charging station: <http://www.learnbydestroying.com/jeffl/crud/India-power.jpg> (The stand and platform on the left is a cell phone charging station). While minimalist design is a worthy exercise, finding a problem worth solving is more difficult and methinks more interesting. -- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558
Reply by ●February 7, 20182018-02-07
On Wed, 7 Feb 2018 05:03:57 -0800 (PST), tabbypurr@gmail.com wrote:>By useful I mean in areas of the developing world where electricity >is available to a percentage of users.Or, a percentage of time. I'm told that power in the developing world is often intermittent and unreliable. I have that problem living in the forest, where the power wires are known to attract falling trees. Damage to electronics from voltage surges usually occurs when the power is restored, so I unplug or turn off (at the breaker panel) power to any sensitive devices. The problem is that in the middle of the night, there's no easy way for me to determine that the power had been restored. So, I built a "Power Restoration Wake Up Alarm" that makes loud buzzing noises when power comes back. This might be a bit too complicated for the proposed design project. Instead, I suggest inserting a small power diode (1N4002) into the wall outlet. When the power returns, the diode explodes, making enough noise to alert or wake the residents. It can't get much simpler than a single diode. -- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558
Reply by ●February 7, 20182018-02-07
On 2/7/2018 10:09 AM, Jeff Liebermann wrote: <snip>> Instead, I suggest > inserting a small power diode (1N4002) into the wall outlet. When the > power returns, the diode explodes, making enough noise to alert or > wake the residents. It can't get much simpler than a single diode.Simple, but idiotic. A single tiny explosion isn't going to do much. When the power goes out connect an 18650, unprotected, Li-Ion battery into the wall outlet. When the power is restored the Li-Ion battery will explode and start a small fire which will then trigger the smoke alarm. The continuous alarm is more likely to be effective.
Reply by ●February 7, 20182018-02-07
Jeff Liebermann <jeffl@cruzio.com> wrote:> Developing world? A fairly high percentage of people in Africa have > cell phones or smartphones (to discourage POTS line copper theft):Over here, making such a statement would result in you being called a RACIST and being trending on Twitter all day.
Reply by ●February 7, 20182018-02-07
On 02/07/2018 10:09 AM, Jeff Liebermann wrote:> On Wed, 7 Feb 2018 05:03:57 -0800 (PST), tabbypurr@gmail.com wrote: > >> By useful I mean in areas of the developing world where electricity >> is available to a percentage of users. > > Or, a percentage of time. I'm told that power in the developing world > is often intermittent and unreliable. I have that problem living in > the forest, where the power wires are known to attract falling trees. > Damage to electronics from voltage surges usually occurs when the > power is restored, so I unplug or turn off (at the breaker panel) > power to any sensitive devices. The problem is that in the middle of > the night, there's no easy way for me to determine that the power had > been restored. So, I built a "Power Restoration Wake Up Alarm" that > makes loud buzzing noises when power comes back. This might be a bit > too complicated for the proposed design project. Instead, I suggest > inserting a small power diode (1N4002) into the wall outlet. When the > power returns, the diode explodes, making enough noise to alert or > wake the residents. It can't get much simpler than a single diode. >How about an ac relay, normally open type, in the power line input to the gadget you want to protect, with the coil powered from the "on" contact side. Power drops out, relay disconnects from power line, power comes back but will not energize the relay until you manually reset it, by pushing the contactor down by hand. Use a stick to push it!
