EEVblog Electronics Community Forum
Electronics => Projects, Designs, and Technical Stuff => Topic started by: coppercone2 on October 04, 2024, 07:15:08 pm
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my hp meter has a 'indian bead' specified in the errata. It disintegrated during disassembly.
Is this just a insulator? It says it prevents the ferrite from touching the case. But does it do anything RF wise?
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Have not hear them called "indian" but I have seen small plastic beads used as insulators or spacers in some old HP equipment. The ones I saw are hard and almost clear. Definitely just insulators or spacers.
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my hp meter has a 'indian bead' specified in the errata. It disintegrated during disassembly.
Is this just a insulator? It says it prevents the ferrite from touching the case. But does it do anything RF wise?
It sounds like a plain plastic bead that was used to space the base of a part (such as a power transistor) up and away from the metal chassis or through the CENTER of a larger hole in a metal heat sink. If so then it shouldn't have any effect on the circuit.
I've never heard the insulators called Indian beads but I'm sure that that is a reference to the brightly colored European manufactured beads that the early Dutch, French, Spanish and English traders used to trade to the American Indians.
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That it disintegrated implies it was organic?
I go to the local hippy bead store if I need spacers. Most are glass.
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Sometimes the spacer beads are ceramic, if temperature is a problem.
Here is an Indian source for what are normally called "fish-spine" beads (because of how they stack for longer wires): https://in.misumi-ec.com/vona2/detail/222005942938/?HissuCode=RG-4#
These beads allow reasonable flexing for a wire inside them, as the curved surfaces articulate.
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it looked like a blue doughnut and it cracked into many pieces is what I mean. I thought it was glass-like. Fell on the floor somewhere as usual
I can just cut a segment of teflon tube instead if its just a insulator. I thought it might have been a complimentary ferrite type
I never saw multiple materials stacked up together, but its possible
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Maybe nothing to do, but some months ago I'd read the english version of a chinese paper about a MCU core and then I saw SFR_Indian_Addr. Maybe it was a bad translation of the SFR_Indirect_Addr label in chinese.
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If it is not attracted to magnets, then it is not ferrite.