anyone know these symbols in a block diagram? - Page 1
Forum section: electronics / beginners

author: LektroiD
author_rank: Frequent Contributor
timestamp: August 18, 2015, 11:29:09 am
content: 3rd page:http://www.spontis.se/pdf/etivocoder.pdfsome of the blocks have an AC symbol inside which include an AC symbol with a front slash through the symbol, in a few of them there are the AC with the slash, then underneath the AC without the slash, then the AC with the slash. Others have one of each.Then there's the blocks with the X in the middle.I'm not familiar with these symbols. I've done a few searches, but can only find standard schematic symbols which I'm already familiar with. Is there a list of these block diagram symbols anywhere, or could someone at least explain what they mean?If I can get hold of a book listing every symbol used in electronics (including these) with a description, that would be even better...

author: RobertHolcombe
author_rank: Frequent Contributor
timestamp: August 18, 2015, 11:35:31 am
content: Guessing high pass, low pass and band pass filters, interested to hear what they actually areEDIT: there is actually one labelled HPF before Output to mixer 1, which matches, so guess I'm correct

author: fcb
author_rank: Super Contributor
timestamp: August 18, 2015, 11:46:27 am
content: Roberts quite right. Filters (low pass, high pass, bandpass all shown).The X is typically a mixer (shown in a circle), but in these cases it is a multiplier (VCA).I remember the powertran synth and vocoder being published in ETI!!!

author: Andy Watson
author_rank: Super Contributor
timestamp: August 18, 2015, 11:47:29 am
content: Quote from: RobertHolcombe on August 18, 2015, 11:35:31 am+1. Common short-hand for filters.

author: LektroiD
author_rank: Frequent Contributor
timestamp: August 18, 2015, 12:00:16 pm
content: Quote from: fcb on August 18, 2015, 11:46:27 amI found my way there via theMFOS vocoderwhich I've just finished building, scouring around trying to fathom why my lowpass has bleed-through (and a little from the high pass when the mic input is at certain levels).Surprised I've never encountered those symbols before now.

author: dentaku
author_rank: Frequent Contributor
timestamp: August 18, 2015, 01:01:09 pm
content: By the way, Julian Ilett has done some videos of the ETI Vocoder he's planning to build.

author: vk6zgo
author_rank: Super Contributor
timestamp: August 19, 2015, 03:34:17 am
content: Quote from: LektroiD on August 18, 2015, 11:29:09 amThe former are very common symbols used in Comms block diagrams.With two sinewaves shown:-If the top sinewave is slashed out,it is a Low Pass Filter (LPF)If the bottom one is slashed out it is a High Pass Filter (HPF)With three sinewaves shown:-If both top & bottom are slashed out,it is a Bandpass Filter (BPF).If the middle one is slashed out,it is a "notch" filter.(Band Stop filter)asfcbsays:- the one with the "X" is normally a mixer,but not in this case.I edited this before,because after mis-reading Richard's posting,I thought I was wrong about the Bandpass Filter,but Googling verifies what I said earlierSenility has been deferred for a while!;DA symbol with three unslashed sinewaves is a so-called "All Pass Filter"( it is really a wideband BPF,as all real circuits are,in any case.)

author: Richard Crowley
author_rank: Super Contributor
timestamp: August 19, 2015, 04:22:46 am
content: The blocks are all rather well labeled.The blocks with multiple sine waves are filters.A block with a slash across the lower wave is a low-cut or high-pass filter.And conversely, a slash across the upper wave is a low-pass or high-cut filter.And the box with three waves typically shows a band-pass filter which is a combination of low-cut and high-cut.The box with the big X is labeled as a Voltage Controlled Amplifier (VCA).Likewise the Envelope Follower, Sample and Hold, and Mixer boxes are nicely identified.I don't see any boxes on the block diagram that are NOT identified right there on the same page.