Geez that's something I haven't used in years. Built mine into a box with an isolation transformer as well, as voltage and current meters. Expensive little box if you had to pay for it.Originally Posted by Johnno
Hehe.. That was me trying to be funny.. lol /fail
In reality - 2 grownUp Kids that have left home but still ring me and ask for money..Lucky me.
@ wotnot, Those 4.7nf Caps won't take that long to replace.. Seems the casing has deteriorated - could be some sort of wax or is it plastic ?
Oh, The hardware is so sexy...
I still have a 240v Variac to bring out of my workbench weapon arsenal if I feel threatened in anyway.. lol
Good to see this old gear getting some well deserved air and exposure =)
Just a side note wrt those ES460C rectifier bricks ~ I contacted the seller about the RIFA caps in them, indicating if the buyer wasn't savvy to this, a mains voltage power-up will be all sorts of magic blue smoke & fireworks....which is true, these things fail spectacularly =)
He indicated he would have to do something about that, change the listing or whatever...no idea myself.. but don't be surprised if these brinks get cheaper.
Johnno (08-05-20)
I've had a few of those go off in old computer gear. Notably my Microbee "Computer in a Book" and an old DEC VT180 external floppy drive unit. It's quite spectacular: makes a loud "snap, crackle" sound and releases enormous quantities of very stinky smoke... but then the power supply keeps running. Throws you the first time it happens!
Yeah me too Bob, It's been a couple of years since I've used my Variac.. I really dig your home built unit though Well Done putting that together.
Yes they are an expensive box, but back in the days I couldn't do without it.
Today, I do very little board repairs, mainly personal or mate fixes. I think 35 years is long enough.
I always wonder whether the Electronic Repair Service line is a dying trade ??
I do know that at current situation many consumers prefer to buy New rather than repair because electronic equipment is getting cheaper and cheaper.
Nice blast from the past there, haven't seen any Warburton Franki gear for a long long time =)
They're still going as well ...
Somewhat Relevant, What is a Dangerous voltage Level for power supply type outputs?
Yeah, I know you can get hit with 20K Volts from a magneto and it hurts but won't ordinarily kill some one because of the current or lack thereof but what about supply voltages with amp level currents??
I was playing with some panels up the back and reading 90V which was as the 3 panels were rated at. I accidentality touched the wires and didn't feel anything. I then deliberately brushed them waving my hand so if I were shocked, momentum would make it brief but I still couldn't feel anything. Tentatively I grabbed hold and if not for 2 Volt meters reading the same thing, I wouldn't have known the wires ( held both) Were even live. I threw on another panel then another and it wasn't till I got to the 130V -IF- I held tight to make good contact I could start to feel it. It certainly didn't hurt, I could feel a slight buzzing which surprised me seeing this was dc but it wasn't painful of belted me Like an Ignition spark. I could have easily gone higher but I chickened out not knowing what the effects and threshold of danger and damage to ones body Might be.
I have made a serious habit of avoiding live wires and have read that is especially important with DC so I don't know what I should feel and what is dangerous.
I know US AC power is 110 and they always talk about electrocution and danger with that but will AC belt you harder than DC? I thought it was the other way around?
Don't have a vairac to work my way up the AC scale but just wondering what the danger levels are and where the discomfort comes in?
Johnno (09-05-20)
It all depends, "DC is constant, while AC is alternating and falling in amplitude in the cycle, so DC will give the stronger field, except at the peak voltage of the AC cycle, when AC will be stronger.
At the RMS voltage they will be equal but maybe of opposite sign, depending on the part of the ac cycle.
One of the reasons that AC might be considered more dangerous is that it arguably has more ways of getting into your body.
Since the voltage alternates, it can cause current to enter and exit your body even without a closed loop, since your body (and what ground it's attached to) has capacitance. DC cannot do that."
Last edited by Johnno; 09-05-20 at 12:00 AM.
110 V (or 240v household voltage pretty much) is dangerous (i.e. can kill you) I think there's consensus on this, no need to try
So I guess there's two parameters here, voltage and current... I used to get zapped from the old telephone wires.. lol maybe 48v ?
It's power that kills, or better yet, current through vital organs which depends on the current capacity of the source and its voltage..
However, depending on how "conductive" you are at any one time, sometimes e.g. 50V might be quite safe and other times it may kill you.
9v batt won't hurt you but a 1.5v cell pack will give a decent kick..
Last edited by Johnno; 08-05-20 at 11:58 PM.
It depends on how sweaty you are. I remember being surprised to feel a tingle from a 48v DC system, but it was in the middle of Summer with no air con.
Yes, I was building a boat trailer once, middle of summer in the shed. I was wearing overalls and sat on the trailer and took off my glove to change the electrode in the old stick welder I was using. When I grabbed the electrode with my sweaty hand, I got a boot up the bum from where I was sitting on the neg connected trailer frame, in my sweaty overalls.
When I was repairing welders for a living, the two common complaints were 1) The VRD (drops O/P voltage down to 11-12V until the arc is struck) wasn't working, and people were getting tingles. And 2) it was hard to strike an arc, because the VRD was working... LOL
Yes, I gave up repairing electronics as a business 20 years ago, just when MWOs and TVs started getting very much cheaper. I went back to working on Aeroplanes for about 7 years, then after taking a redundancy went on to working of industrial electrical gear. (welding, plasma cutting, CNC etc). Did that for a couple of years, then into Auto Elec work on mining equipment (Trucks, Utes, Blast Hole Drill Rigs), and wiring up Power Switching Rooms.
Been retired for about 5 years now, and sold off a lot of my gear, so only do the odd repair for friends and family, or if I find something nice in the way of vintage stereo gear. I have picked up some really cheap gear from the mid 80's onwards for not much money, or even free, and repaired or just cleaned up and serviced (pots caps etc) and flipped them for a decent profit, but not really making a business of it.
Johnno (09-05-20)
It all has to do with galvanic skin resistance/potential, there's considerable study on it, and many variables (including exactly which part of the body contacts the electrical current). Indeed, another thing that effects a person's GSR/GSP, is age -- this is why many older folks find touch-screens don't work properly for them.
LOL.. I've lost count how many times I've been zapped touching live circuits.. lol
I have an electric shock scar tattooed on my elbow and another on my index finger.. lol
Once, I was thrown across the room.. lol Got up and throw the bloody power supply out the window... Never to be seen in service again.. lol
Time to compare all the scars from electric shocks... LOL
Same here, although I'm too lazy to go source it ; repairs have to come to me, and leave of their own accord =) Sitting on the bench currently, is an old Sanyo receiver (from the days when Sanyo made decent stuffs =)Been retired for about 5 years now, and sold off a lot of my gear, so only do the odd repair for friends and family, or if I find something nice in the way of vintage stereo gear. I have picked up some really cheap gear from the mid 80's onwards for not much money, or even free, and repaired or just cleaned up and serviced (pots caps etc) and flipped them for a decent profit, but not really making a business of it.
Jma should edit the thread title and add 'includes old school equipment pictorial' ....
Johnno (09-05-20)
LOL.. I've lost count how many times I've been zapped touching live circuits.. lol
Time to compare all the scars from electric shocks... LOL
Closest I've come, was having one of those old metal cased B&D electric drills in one hand, and with the other hand went to pick up a still connected mains transformer...and my fingers found active ; drill went one way, transformer went the other, and I went in a 3rd direction backwards and into the wall. Memories of nearly killing oneself tend to remain very vivid ...I have many (used to ride streetbikes =)
Hehe... I really like those old receivers, easy to work on. Great stereo sound.
Components could be sourced from RS, Altronics, Jaycar even Tricky Dicky (dick smith).
Not like todays circuit boards that are Multi layered, miniaturised and it's becoming impossible to repair without a circuit diagram and a magnifying glass.
Hey, I see a dry joint on that resister right over there.....LOL yep that one..
Last edited by Johnno; 09-05-20 at 01:02 PM.
50v DC from telephone exchanges won't kill you, ringer will give you a nasty jolt. 75v ac makes you jump when the phone rings whilst you are working on the line. Got many scars on the back of my hand from contacting a ringing line whilst trying to trace a jumper on an MDF..... Shouldn't kill you, but, it has been known to happen. I've been bitten by 240v only once, I resolved never to do it again. So far, so good. Had a (dearly departed) mate who was a sparky and had been bitten numerous times. Once by HV which, fortunately, chucked him off the ladder and he hit a barbed wire fence on the way down which happened to re-start his heart. A few years later he got hit again, but there was little to save. His heart was "mush" after being spiked many times over the years. Was a great bloke, too.
I'm out of my mind, but feel free to leave a message...
wotnot (09-05-20)
I saw it once reckoned somewhere, that for every time you become part of an electrocution event, even if you survive such, it takes 5years off your expected lifetime in the process... every time it happens ; death by a 1000 sparksA few years later he got hit again, but there was little to save. His heart was "mush" after being spiked many times over the years. Was a great bloke, too.
'Sorry about that chief'...Max said, 'I forgot it was me who created this thread topic' ... facepalm, 10 lashes with cat of 9 tails...10minutes standing on the red-ant mound...Jma should edit the thread title and add 'includes old school equipment pictorial' ....
Last edited by wotnot; 09-05-20 at 05:52 PM.
Did this for afternoon entertainment...pulled all 3 down, but did viddy one...
I am jealous of all you electronic Wizards.
I was interested in it as a Kid. Hounded my parents insane to buy me one of those Electronic Build Kits from Tandy ( Radio Shack in the US) . Life and a lack of smarts got in the way of following it though but over the last couple of years I have spent a bit more time learning things and I'm only 90% dumb with it as I used to be.
The more I learn the more I am in awe of those that actualy know about it. Really just does seem like complete and utter magic to me.
On another forum I am on there are a bunch of guys, mainly retired that build inverters for off grid applications mainly and it absoloutley facinates me how they can sit down and design these things. I posted some questions earlier in the year about wanting to make a devise that I could put between solar panels and a water heater to keep the panels on VMP like a voltage operated switch. About 3 Hours later I look again and this wizzard has designed a simple as circuit to do it. Then he says I have to have some boards printed, I'll get some done for you.
Few weeks later they arrive.
I'm having trouble making them work which is Fking embarrassing because I know it's me not the boards. Been waiting a couple of months now for new components to try again but half haven't arrived with the china flu. I am trying to get my hear around how to program an arduino to turn on at a low programed voltage( through a voltage Divider) and then turn off at an upper limit. Having trouble getting my head round that and every sketch I try to copy and modify is different to another I have seen.
I tell you, it's fking hard and frustrating being Dumb! Unfortunately my cognitive abilities are not getting any better. I'm waiting for this China flu to be over to see if I can see someone to help me get my head fixed.
I am also fascinated how you wizards can look at a Circuit with hundreds of components and work out what the hell is wrong with it, often without the schematic.
Electrics isn't too hard for me, I can figure that out because that's pretty hammer and nails although I come across so many people that have no idea of that as well.
Was talking to my neighbour about solar this afternoon and was asking about putting some more panels and an inverter on his shed. He was telling me how he dug the trench and put the wiring up there and I was asking if he knew what size cable was installed and what the breaker rating on the circuit was? He kept on telling me it was all 240 up there! All his gear is 240! Umm, yeah. Has to be 2.5 Minimum but is it any larger wire? I asked if he had 3 Phase? NO! that's a pain in the arse! Ummm, OK.
I was looking at the sub board in the shed then he pulls a panel back and says that's where the cable comes in. Turns out he does have 3 phase in 6mil but looks like only one phase is connected in the shed.
OK, that 4 Kw inverter is not going to be a problem. We can put 2 up here if you want. Then he starts telling me that he had it set up so the house uses the power first then it goes back to the grid, that's what he asked for because that's the smart way of doing it..... Umm, yeah.... I don't know any other way of doing it on domestic but anyway. :0)
He's a very nice bloke and he's very cluey but electricity in not quite his forte. Never mind, I can hook it all up for him. Might just ask his Mrs to take him out for the day while I do it. Will be much faster that way! :0)
Electrics is a walk in the park but electronics,.... wow.
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