Cheap Multimeter Leads Come With Extra Ohms, Free!

[Nop head] discovered that cheap multimeter leads costing only a few bucks can come with more than one may have bargained for. The first set had a large amount of useful-looking attachments, but the wires used for the leads were steel with a resistance of about one ohm each. With two leads in use, that means any resistance measurement gets two ohms added for free. More seriously, when measuring current, the wires can heat up rapidly. Voltage measurements would be affected the least, but the attachments and lead design expose a large amount of bare metal, which invites accidental shorts and can be a safety hazard with higher voltages.

Are all cheap multimeter leads similarly useless? Not necessarily. [nop head] also purchased the set pictured here. It has no attachments, but was a much better design and had a resistance of only 64 milliohms. Not great, but certainly serviceable and clearly a much better value than the other set.

It’s usually not possible to identify garbage before it’s purchased, but [nop head] reminds us that if you do end up with trash in hand, poor quality counterfeits can be good for a refund. That goes for electronic components, too.

PCBs Without Any Substrate

[Kimio Kosaka] is taking the concept of free-formed circuits to the next level with O’Baka Project No.7. It’s a fully functioning Arduino board, without the board. The traces are there and provide all of the support for the rest of the hardware. You can imagine the fragility of the package so it won’t be a surprise to learn that O’Baka Project means ‘stupid’ project.

We don’t think this manufacturing process is completely worthless. The ‘board’ seen above looks quite interesting and might be a good idea when building a show-piece where you want the circuitry to be seen. [Kimio] describes the process he used to achieve this look. The first step is to design a single-sided circuit board; he used EagleCAD. After printing out the traces he used 0.46mm steel wire to trace out each connection. Now heat up that soldering iron – [Kimio] recommends using high-acid flux to ease the process of soldering to the steel.

We think this would nicely compliment projects like LED cubes that use the circuit itself as a support structure. See this Arduino alternative from several different angles in the video after the break.

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