Have you ever wanted to measure the current consumption of a battery powered device, but found that you need two hands to hold wires against the battery, and your other two hands to hold wires against the battery contacts, leaving you with not ernough hands free to operate the device itself? Here's a way to reduce the required number of hands.
The probe itself is made from FR-4 double-sided copper clad board, nominally 0.2mm thick (actually 0.25mm including the copper layers). At that thickness it's easily cut with scissors, and very flexible. This stuff is cheap, but not widely available. I found some on Ali Express.
After cutting it into a long shape narrow enough to fit against a battery contact, I carefully sanded the edges to make sure no copper bridged the two sides. I soldered a wire to each side of the board, making sure not to bridge the two sides with solder, and attached a 4mm banana socket to the other end of the wires, for connection to a multimeter or oscilloscope. Here's what the completed probe looks like:
And a closeup of the tip, where you can just about see the individual layers of glass and copper:
It's so thin that it can be slipped between a battery and a contact, diverting the current through the wires instead. Here it is inserted into the back of a DE-5000:
And finally a shot of using it with a multimeter to measure the actual current consumption of the DE-5000:
If you're curious, the DE-5000 uses 20mA when measuring a capacitor (as shown in the photo), 16mA when idle, and a mere 2µA when off.
The probe itself is made from FR-4 double-sided copper clad board, nominally 0.2mm thick (actually 0.25mm including the copper layers). At that thickness it's easily cut with scissors, and very flexible. This stuff is cheap, but not widely available. I found some on Ali Express.
After cutting it into a long shape narrow enough to fit against a battery contact, I carefully sanded the edges to make sure no copper bridged the two sides. I soldered a wire to each side of the board, making sure not to bridge the two sides with solder, and attached a 4mm banana socket to the other end of the wires, for connection to a multimeter or oscilloscope. Here's what the completed probe looks like:
And a closeup of the tip, where you can just about see the individual layers of glass and copper:
It's so thin that it can be slipped between a battery and a contact, diverting the current through the wires instead. Here it is inserted into the back of a DE-5000:
And finally a shot of using it with a multimeter to measure the actual current consumption of the DE-5000:
If you're curious, the DE-5000 uses 20mA when measuring a capacitor (as shown in the photo), 16mA when idle, and a mere 2µA when off.
