Farm Radio A-B Battery Box

prusaprinters

This is a battery box I made to hold 10 9v batteries and 2 “D” cell batteries to simulate an A-B battery that is used in the vintage tube radios.The 9v batteries are connected in series to produce the 90V B+ voltage needed for the plate. Each of the batteries can be tapped to create lower voltages (9v, 18v, 27v, 36v, 45v, 54v, 63v, 72v, 81v, 90v).The filament voltage is generated using one or two “D” cell batteries. These “D” cell batteries can be connected in parallel 1.5v with more current capability or in series to produce 3V.The lid has holes to mount 6 banana jacks. Two are used for the filament supply and four are used to provide different B+ voltages. Just connect the jacks to the appropriate point in the 9v battery string.I have provided grouped STEP and STL files as well as the individual parts broken into separate STL files.The Eveready graphic is just a picture of an old battery that I stuck on the box to make it look more authentic.Here are the parts I used:Amazon.com: ZZLZX D-Cell Battery Holder 4PCS 72x40x50 mm / 2.83x1.57x1.96 Inches Series or Parallel Physical Science Plastic D Size Battery Case Physics D Battery Holder : ElectronicsAmazon.com: Yohii 9V Battery Box Case Holder Battery Case Holder Replacement - Pack of 10pcs- (G7.23) : Health & HouseholdAmazon.com: bnafes 4mm Banana Socket Kit Terminal Banana Binding Post Connector Jack Compatible for Arduino 10 Pairs : Electronicsuxcell Terminal Strip Screw Terminal Barrier Block 3A 12 Position Dual Row Type U Wire Connector 3pcs: Amazon.com: Industrial & ScientificAssembly:I soldered each of the 9v battery wires together in a daisy chain. I then cut the terminal block into individual connectors and used one connector for each of the daisy chain connections. This allows me to use the other side of the connector to tap an intermediate B+ voltage.I wanted a 1.5V filament supply, so I wired the “D” batteries in parallel and wired the battery holder to the face plate bind post.