{"id":5450,"date":"2016-05-28T09:09:07","date_gmt":"2016-05-28T09:09:07","guid":{"rendered":"http:\/\/tech-ops.co.uk\/next\/?page_id=5450"},"modified":"2016-05-28T09:09:07","modified_gmt":"2016-05-28T09:09:07","slug":"batteries-and-multimeters","status":"publish","type":"page","link":"http:\/\/tech-ops.co.uk\/next\/batteries-and-multimeters\/","title":{"rendered":"Batteries and Multimeters"},"content":{"rendered":"

David Denness<\/strong><\/h3>\n

What happened to B size batteries?
\nWe have AA, AAA, AAAA, C, D.<\/p>\n

Geoff Fletcher<\/strong><\/h3>\n

There is or was a B size battery – also known as a U10. It was used in  two battery mini torches.<\/p>\n

John Howell<\/strong><\/h3>\n

These letters stem from the requirements of valve (tube) radios. <\/p>\n

The ‘A’ battery supplied filament current at 1.5 Volts, the ‘B’ battery HT at 67.5 to 120 Volts, and the 9 Volt ‘C’ battery provided grid bias voltages at typically 3, 4.5, 6, & 7.5 Volts.<\/p>\n

But it’s got out of hand now with 1\/2 & 2\/3 AA, Lithium DD (\u00a348 from RS) and not a ‘B’ battery in sight! (unless you count the Eveready ‘Bijou’ 3 Volt).<\/p>\n

Dave Mundy<\/strong><\/h3>\n

My TMK500 analogue multi-meter has a B154 battery (15 volts, square section) for the higher resistance ranges.  I don’t use the meter any more since Lidl sold some nice digital ones: it was used in the past on ‘real’ TVs etc. (i.e. valve stuff!).<\/p>\n

John Nottage<\/strong><\/h3>\n

I’ve got one of those TMK500 analogue multi-meters! I think I paid \u00a39.19s.6d for mine so it was pre-decimal. I think I still have the receipt somewhere! Still use it too – though there’s a space where the 15V battery is supposed to go. I seem to remember having to chuck the battery years ago when it died and being unable to find a replacement. I’ve an Altai Digi meter too, also years old.<\/p>\n

Dave Mundy<\/strong><\/h3>\n

John probably bought at the same shop as me – Gilberts in the Grampians, Shepherds Bush! I bought mine after someone else on my crew got one,  they were very popular (\u00a38.10s.!)<\/p>\n

Keith Wicks<\/strong><\/h3>\n

It’s much safer to use a low-voltage digital meter for the higher resistance ranges. A 15-volt resistance meter can damage modern solid-state circuits. I learnt this the sad way.<\/p>\n

Not quite so severe as my ancient (1950s?) oscilloscope, which puts a pulse of several hundred volts on the circuit being investigated if you change ranges while the probes are connected. I have a fried detector diode to illustrate this.<\/p>\n

Mike Jordan<\/strong><\/h3>\n

My hand wound and my mains operated Meggers (seem to have OB section 5 on them – whatever that means) both are 500v units.  Made by Mr Evershed and Vignoles who had the factory in Acton Lane.<\/p>\n

Mr Vignoles was also famous for inventing "flat bottomed rails" which, as opposed to figure 8 ones, didn’t rock and roll when trains went around corners and fall out of the sleepers.  There are some of those used as handrails in Brentford Station – so there!<\/p>\n

Their sportsground was across the road from us and, since they became AVO  and moved to Dover, has been a club, a 7th Day Adventist school and soon to be a free school.<\/p>\n

Dave Plowman<\/strong><\/h3>\n

We probably all remember the AVO 8 as being the meter of choice for our studio engineers, etc at one time. <\/p>\n

They were still on sale new last time I looked – but at about \u00a3700. <\/p>\n

I picked up a very good condition used one – complete with real leather case – at an autojumble not that long ago, for a very modest sum. <\/p>\n

<\/p>\n

 <\/h1>\n

\"ianfootersmall\"<\/p>\n

<\/p>\n","protected":false},"excerpt":{"rendered":"

David Denness What happened to B size batteries? We have AA, AAA, AAAA, C, D. Geoff Fletcher There is or was a B size battery – also known as a U10. It was used in  two battery mini torches. John … Continue reading →<\/span><\/a><\/p>\n","protected":false},"author":6,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_coblocks_attr":"","_coblocks_dimensions":"","_coblocks_responsive_height":"","_coblocks_accordion_ie_support":"","advgb_blocks_editor_width":"","advgb_blocks_columns_visual_guide":"","_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"ngg_post_thumbnail":0,"footnotes":""},"categories":[],"tags":[],"class_list":["post-5450","page","type-page","status-publish","hentry"],"coauthors":[],"author_meta":{"author_link":"http:\/\/tech-ops.co.uk\/next\/author\/alec\/","display_name":"Alec Bray"},"relative_dates":{"created":"Posted 10 years ago","modified":"Updated 10 years ago"},"absolute_dates":{"created":"Posted on May 28, 2016","modified":"Updated on May 28, 2016"},"absolute_dates_time":{"created":"Posted on May 28, 2016 9:09 am","modified":"Updated on May 28, 2016 9:09 am"},"featured_img_caption":"","featured_img":false,"series_order":"","_links":{"self":[{"href":"http:\/\/tech-ops.co.uk\/next\/wp-json\/wp\/v2\/pages\/5450","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/tech-ops.co.uk\/next\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"http:\/\/tech-ops.co.uk\/next\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"http:\/\/tech-ops.co.uk\/next\/wp-json\/wp\/v2\/users\/6"}],"replies":[{"embeddable":true,"href":"http:\/\/tech-ops.co.uk\/next\/wp-json\/wp\/v2\/comments?post=5450"}],"version-history":[{"count":1,"href":"http:\/\/tech-ops.co.uk\/next\/wp-json\/wp\/v2\/pages\/5450\/revisions"}],"predecessor-version":[{"id":5451,"href":"http:\/\/tech-ops.co.uk\/next\/wp-json\/wp\/v2\/pages\/5450\/revisions\/5451"}],"wp:attachment":[{"href":"http:\/\/tech-ops.co.uk\/next\/wp-json\/wp\/v2\/media?parent=5450"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/tech-ops.co.uk\/next\/wp-json\/wp\/v2\/categories?post=5450"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/tech-ops.co.uk\/next\/wp-json\/wp\/v2\/tags?post=5450"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}