LOVED the taped PCBs .
I also started over 40 years ago and way back then, Bishop Graphics "precision slit" black crêpe tape and self adhesive pads was the "hi tech" preferred way to go.
Thanks for reviving lost memories
In 1968 I developed the etching process, with a contact photo negative and designed an etch tank using a fish tank pump, some PVC pipe and a hot plate. The board you see was made using my home made equipment. I sold the equipment to a small company and bought a nice car.
wow ! your work from 1968 ---is impressive ----works of art! I see you are a veteran of electronics ---scary dudes--
NOW I am too ashamed to post my home made circuits-- way out of my league here
---must be a forum for beginners somewhere ----
I DID attempt to post a foto at the gallery ---followed a maze of instructions
uploaded a foto for J FAHEY --( asked where I live in the 3rd world)
but it does not appear anywhere---
( not too experienced with PC jargon --
why no simple paperclip icon ---whats with all the 3rd degree interrogation just to post a foto ? --don,t understand half of what cryptic codes are required--
can u enlighten me to a simpler method of attaching fotos?
NOW I am too ashamed to post my home made circuits-- way out of my league here
---must be a forum for beginners somewhere ----
I DID attempt to post a foto at the gallery ---followed a maze of instructions
uploaded a foto for J FAHEY --( asked where I live in the 3rd world)
but it does not appear anywhere---
( not too experienced with PC jargon --
why no simple paperclip icon ---whats with all the 3rd degree interrogation just to post a foto ? --don,t understand half of what cryptic codes are required--
can u enlighten me to a simpler method of attaching fotos?
Your desire to learn is great, don't worry how it looks we just want to help. My first experiment at age 7 resulted in a dark garage and some sparks. You could use Flicker to post some pics, if that works I will tell you what to do next.
https://www.flickr.com/
Mooly has posted a detailed method to attach pics.
Start with "Go Advanced" instead of Post Quick Reply.
NOW --i find how to attach a schematic!
what a cryptic method to find a simple attach icon!
spent hours on trying to figure out how " gallery " works
--failed
Wayne suggested Flicker ----so I had to sign up /register
---still got into trouble ---
and then ----
well thanku mr MOOLA for the shortcut --had no idea " go advanced '
MEANT " HERES a easy method to attach "
really appreciate --now I can post schematics to Wayne & others---without
further complications--
thanks a million --
ok --here,s a test foto ( my banana republic home)
what a cryptic method to find a simple attach icon!
spent hours on trying to figure out how " gallery " works
--failed
Wayne suggested Flicker ----so I had to sign up /register
---still got into trouble ---
and then ----
well thanku mr MOOLA for the shortcut --had no idea " go advanced '
MEANT " HERES a easy method to attach "
really appreciate --now I can post schematics to Wayne & others---without
further complications--
thanks a million --
ok --here,s a test foto ( my banana republic home)
Attachments
thanks wsj ----appreciate-
unfortunately 15 volt DC only causes huge distortion in tha TDA 2040 AMP
--- has to be 19 -22volt-
( 2 x 12 volt batteries in series and it amplifies perfect ! 2 VOLT less --crackle rumble !--
built it months ago ----both circuits /split supply --both need 20 volts minimum
to stop growl /buzz oscillation -
by the way the 19 volt PC power supply ---works ok ---JUST marginal -
NOW---I have a problem finding --in all those sgs THOMSON PDF DATA sheets-
the minimum AMPERAGE DRAWN BY THE TDA 2040--- only shows many
graphs on power/voltage relations-- tells all about input /inverse voltages -etc etc
but NOWHERE can I see what ACTUAL AMPS IT USES /REQUIRES /DRAWS?
the reaso being --the PC 19 volt supply I use now ---is rated 2.1 amps -
max -----I am sure the TDA is pulling more than that -?--as it clips
oscillates on overdrive with fx pedals-- but I am very far from competent on amps-
ok --going to get busy building your rectifier circuit I saved --thanku so much for all the help ----
FAHEY mentioned a TO 220 voltage regular ---is rated only to 15 volt max !
but its going to be months b4 my radioshack supplier will get my transformer & those darlington pair power transistors ---
just have to wait ---or search salvaged scrap ----good fun - !( only identified alien parts last week as being -not 220 ohm resistors ---but "" RADIAL inductors "--220 m henries ------so still learning !
unfortunately 15 volt DC only causes huge distortion in tha TDA 2040 AMP
--- has to be 19 -22volt-
( 2 x 12 volt batteries in series and it amplifies perfect ! 2 VOLT less --crackle rumble !--
built it months ago ----both circuits /split supply --both need 20 volts minimum
to stop growl /buzz oscillation -
by the way the 19 volt PC power supply ---works ok ---JUST marginal -
NOW---I have a problem finding --in all those sgs THOMSON PDF DATA sheets-
the minimum AMPERAGE DRAWN BY THE TDA 2040--- only shows many
graphs on power/voltage relations-- tells all about input /inverse voltages -etc etc
but NOWHERE can I see what ACTUAL AMPS IT USES /REQUIRES /DRAWS?
the reaso being --the PC 19 volt supply I use now ---is rated 2.1 amps -
max -----I am sure the TDA is pulling more than that -?--as it clips
oscillates on overdrive with fx pedals-- but I am very far from competent on amps-
ok --going to get busy building your rectifier circuit I saved --thanku so much for all the help ----
FAHEY mentioned a TO 220 voltage regular ---is rated only to 15 volt max !
but its going to be months b4 my radioshack supplier will get my transformer & those darlington pair power transistors ---
just have to wait ---or search salvaged scrap ----good fun - !( only identified alien parts last week as being -not 220 ohm resistors ---but "" RADIAL inductors "--220 m henries ------so still learning !
Hi,
Willingness to learn is not the same as building something pointless.
A rather drastic measure (but a learning process) might be
rebuilding the transformer modifying the secondaries.
FWIW stick a big electrolytic across the laptop supply
between it and the amplifier, say 3,300uF to 4,700uF.
Local 100nF decoupling very near the chip amplifier.
rgds, sreten.
Willingness to learn is not the same as building something pointless.
A rather drastic measure (but a learning process) might be
rebuilding the transformer modifying the secondaries.
FWIW stick a big electrolytic across the laptop supply
between it and the amplifier, say 3,300uF to 4,700uF.
Local 100nF decoupling very near the chip amplifier.
rgds, sreten.
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May I suggest that this thread is going down the wrong path.
Considering the OP's location there wouldn't necesserially be a steady and constant supply of mains power available.
May I suggest that the TDA2822M or some other integrated amplifier (taken from a tv set/boombox for example) in a mono bridged configuration would be more suitable as the OP can power his creation from solar panels and a single 12v 9AH to 12 amp hour battery for at least a month.
I use one frankenstein prototype of one myself currently in stereo configuration and it amplifies two large speakers to very adequate levels.
Also next time that he passes by a luxury car abandoned on the side of the road I would suggest he steal/nick off with the speakers.
I have some experience scabbing parts from old appliances myself and cannot fathom the reasoning behind wanting a large amount of wattage in a place as remote, from the previous posts other necessary components may be almost impossible to find.
Its hard enough here on my budget to build an amp like that LM3886 as sourcing all of the necessary components is difficult and 99% of the time they have to come from Hong Kong. I think that we need to focus on components which are already available in everyday appliances like car radios, tv's/boom boxes, etc because this is exactly where the OP will be sourcing his components from.
Like the TDA2005.
http://www.st.com/web/en/catalog/sense_power/FM125/CL1503/SC1761
http://www.circuitstoday.com/car-stereo-amplifier-circuit
At least then the OP can go out and acquire some car batteries for his power source. Assuming he can get a solar charge controller (or make one himself with a 555 timer and a relay, there's a schematic out there.) to charge it safely and build a battery box. etc.
Would probably be easier than rewinding a transformer to suit a specific application. We don't even know what the VA rating of the transformer is or weather or not adequate fusing and safety of mains wiring will be taken.
That's my 2c anyway.
Considering the OP's location there wouldn't necesserially be a steady and constant supply of mains power available.
May I suggest that the TDA2822M or some other integrated amplifier (taken from a tv set/boombox for example) in a mono bridged configuration would be more suitable as the OP can power his creation from solar panels and a single 12v 9AH to 12 amp hour battery for at least a month.
I use one frankenstein prototype of one myself currently in stereo configuration and it amplifies two large speakers to very adequate levels.
Also next time that he passes by a luxury car abandoned on the side of the road I would suggest he steal/nick off with the speakers.
I have some experience scabbing parts from old appliances myself and cannot fathom the reasoning behind wanting a large amount of wattage in a place as remote, from the previous posts other necessary components may be almost impossible to find.
Its hard enough here on my budget to build an amp like that LM3886 as sourcing all of the necessary components is difficult and 99% of the time they have to come from Hong Kong. I think that we need to focus on components which are already available in everyday appliances like car radios, tv's/boom boxes, etc because this is exactly where the OP will be sourcing his components from.
Like the TDA2005.
http://www.st.com/web/en/catalog/sense_power/FM125/CL1503/SC1761
http://www.circuitstoday.com/car-stereo-amplifier-circuit
At least then the OP can go out and acquire some car batteries for his power source. Assuming he can get a solar charge controller (or make one himself with a 555 timer and a relay, there's a schematic out there.) to charge it safely and build a battery box. etc.
Would probably be easier than rewinding a transformer to suit a specific application. We don't even know what the VA rating of the transformer is or weather or not adequate fusing and safety of mains wiring will be taken.
That's my 2c anyway.
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This sounds like you do not yet understand how a Power Amplifier draws current.
On power up the amplifier, whether discrete or chip type, draws a quiescent current. this is usually in the range 10mA to 100mA. Sometimes referred to as Iq
When a load is connected and there is no signal, all the current flows from the +ve supply rail to the most negative supply rail. This is still Iq.
Some amplifiers split the Iq into two return paths most to the -ve supply rail and a tiny current to Power Ground.
When signal is present the current drawn from the +ve supply rail increases and the current to the -ve supply rail decreases. The DIFFERENCE in these two currents is equal to the output current.
A typical reactive 2way speaker will draw currents that vary with frequency and with signal. Expect a 50W into 8ohms amplifier without any clipping of the signal (no voltage clipping and no current clipping) to send upto 3.5Apk into a 8r0 resistive load.
When the signal is music and the load is a reactive speaker, the peak current into an 8ohms speaker from an unclipped signal from a 50W amplifier can approach 10Apk and on rare occasions even exceed this.
The PSU has to supply these varying currents, anywhere from 10mA continuous to 10Apk.
You will not find that in a chipamp datasheet. You need to learn how an amplifier works and apply that knowledge to selecting a suitable PSU.
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thanks SRETEN ---
ITS OK NOW --- its settled down --- the 19 volt supply has quietened drastically !
(must have been RF feedback or the fx unit too close ---
its performing brilliantly---no huge electro cap needed --but will bear in mind if it does oscillate or whine again ---
however --I have to build a power supply ---to have he the=satisfaction of DIY-
( But I am having to import that correct 220 --15 V AC transformer/volt regulator
stuff --takes a while --worth the wait
really appreciate the advice --
keep well
ITS OK NOW --- its settled down --- the 19 volt supply has quietened drastically !
(must have been RF feedback or the fx unit too close ---
its performing brilliantly---no huge electro cap needed --but will bear in mind if it does oscillate or whine again ---
however --I have to build a power supply ---to have he the=satisfaction of DIY-
( But I am having to import that correct 220 --15 V AC transformer/volt regulator
stuff --takes a while --worth the wait
really appreciate the advice --
keep well
Thanks Andrew-- here come the questions on that scary analysis of amps ( yes I have limited knowledge of their intricate working mode)but please translate the following-----
1-- quiescent current? --means what exactly --idling under no load? -not drawing power?
2 -- discrete vs chip amp --difference?
3----so---the SPEAKER draws the current?
4 ---all I really worry about --is the 19 volt PC supply --into my TDA 2004 amp
----may not have enough amps to serve the IC ----( ITS RATED 2.1 AMPS -ON the PC supply)------is that sufficient ? will it burn out if I push the TDA amp on guitar overdrive thru a 70 WATT 4 ohm speaker?
( cannot find any amp info on this 2040 in the datasheet --surely the manufactures
have a minimum amp supply requirement?) that's really my question ----is 2.1 amps supply sufficient ?
1-- quiescent current? --means what exactly --idling under no load? -not drawing power?
2 -- discrete vs chip amp --difference?
3----so---the SPEAKER draws the current?
4 ---all I really worry about --is the 19 volt PC supply --into my TDA 2004 amp
----may not have enough amps to serve the IC ----( ITS RATED 2.1 AMPS -ON the PC supply)------is that sufficient ? will it burn out if I push the TDA amp on guitar overdrive thru a 70 WATT 4 ohm speaker?
( cannot find any amp info on this 2040 in the datasheet --surely the manufactures
have a minimum amp supply requirement?) that's really my question ----is 2.1 amps supply sufficient ?
Id, quiescent current is in the datasheet. stated as<=30mA and <=100mA for the two voltage supplies.
Why can't you find this?
Io, maximum output current is stated as 4A. This is 4Apk even though that is not explicitly stated.
the 4r0 (into a dummy resistor load) is stated as 25W with +-17Vdc
assuming +-20Vdc in quiescent state, this is likely to drop to around +-16Vdc if the supply is not regulated. Expect ~20W into 4r0.
20W into 4r0 is equivalent to 3.16Apk & 12.6Vpk. Why can't you read this on your datasheet?
BUT !!!!!
a 4ohms speaker will draw peak currents that are around 2times to 5times what the equivalent resistor will draw.
A 4ohms speaker driven to non clipping 20W can draw currents peaking at around 9Apk.
The tda1020 cannot properly drive a 4ohms speaker with +-16Vdc supplies.
I suggest you use a high efficiency 8ohms speaker.
Why can't you find this?
Io, maximum output current is stated as 4A. This is 4Apk even though that is not explicitly stated.
the 4r0 (into a dummy resistor load) is stated as 25W with +-17Vdc
assuming +-20Vdc in quiescent state, this is likely to drop to around +-16Vdc if the supply is not regulated. Expect ~20W into 4r0.
20W into 4r0 is equivalent to 3.16Apk & 12.6Vpk. Why can't you read this on your datasheet?
BUT !!!!!
a 4ohms speaker will draw peak currents that are around 2times to 5times what the equivalent resistor will draw.
A 4ohms speaker driven to non clipping 20W can draw currents peaking at around 9Apk.
The tda1020 cannot properly drive a 4ohms speaker with +-16Vdc supplies.
I suggest you use a high efficiency 8ohms speaker.
Thanku Andrew ---
ER --- TDA 1020 ? cannot properly drive 4 ohm speaker"--
typo ?" you mean 2040 ?
ok ----
BUT u talk about OUTPUT amps to speaker --yes I saw that in the data sheets-
so --- 4 AMPS---? IS that the TOTAL CURRENT CONSUMPTION RATING A - of TDA 2040?
if so ---that 19 volt power supply may burn out ---its only suppling 2.1 amp
----sounds ok though -- not overheating ( pc 19 volt supply )
the rest is hard to understand --I just build all the TDA --- amps --- they work off
batteries --heavy clumsy --that's why I need to build several different transformer
rectifiers---batteries don,t last --
ER --- TDA 1020 ? cannot properly drive 4 ohm speaker"--
typo ?" you mean 2040 ?
ok ----
BUT u talk about OUTPUT amps to speaker --yes I saw that in the data sheets-
so --- 4 AMPS---? IS that the TOTAL CURRENT CONSUMPTION RATING A - of TDA 2040?
if so ---that 19 volt power supply may burn out ---its only suppling 2.1 amp
----sounds ok though -- not overheating ( pc 19 volt supply )
the rest is hard to understand --I just build all the TDA --- amps --- they work off
batteries --heavy clumsy --that's why I need to build several different transformer
rectifiers---batteries don,t last --
Right on the money --Freax----you know the problem well
scavange parts from mountains of scrap TV /pc table topstype boomboxes
great source of parts --but desoldering with care is difficult --lottsa broken
bits ---
built TDA 2005 ----2006 ---- all are rugged reliable short circuit proof
( idiot proof--as well in my situation ---)
but ultimately ---you have to order from o/seas --takes foreva --
am very pleased with the 19 volt old laptop power supply --light
compact-- TDA 2040 sounds supa ---very little noise
--- mains / load shedding here in the bush a regular nuisance
spikes are order of the day ---damages fridges /TV etc --trying to find
a home made ( what else ) DIY surge protector
thanks for the support--
regards
re
scavange parts from mountains of scrap TV /pc table topstype boomboxes
great source of parts --but desoldering with care is difficult --lottsa broken
bits ---
built TDA 2005 ----2006 ---- all are rugged reliable short circuit proof
( idiot proof--as well in my situation ---)
but ultimately ---you have to order from o/seas --takes foreva --
am very pleased with the 19 volt old laptop power supply --light
compact-- TDA 2040 sounds supa ---very little noise
--- mains / load shedding here in the bush a regular nuisance
spikes are order of the day ---damages fridges /TV etc --trying to find
a home made ( what else ) DIY surge protector
thanks for the support--
regards
re
NEW Desoldering Pump Tool Vacuum Solder Sucker Remover Iron Desolver Accessories | eBay
That solves the desoldering problem.
Now onto the lack of an ever lasting battery.
http://www.ebay.com.au/itm/Nickel-I...Caravan_Parts_Accessories&hash=item3ce6bdbe30
Done.
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