Yes the ground returns are then separate and cannot mix with each other, this is the main advantage of this circuit ... there are a few other advantages that are much more complex, such as events that are unpredictable and transient - modestly protecting equipment from ground induced currents.
Whilst out of the budget of most persons, the best ground conduction involves establishing access to below 20 metres in to the ground, as well as enhancing ground conduction with GEM a graphite substance and copper rods. Such installations can be found at AM radio transmitters. Where there are assets holding equipment like this the cheapest insurance against direct or ground induced lightning strike is deep grounding.
There are many other resistances in the circuit of an amplifier that have more consequence than 1 diode drop. So give it a try.
Cheers / Chris
Whilst out of the budget of most persons, the best ground conduction involves establishing access to below 20 metres in to the ground, as well as enhancing ground conduction with GEM a graphite substance and copper rods. Such installations can be found at AM radio transmitters. Where there are assets holding equipment like this the cheapest insurance against direct or ground induced lightning strike is deep grounding.
There are many other resistances in the circuit of an amplifier that have more consequence than 1 diode drop. So give it a try.
Cheers / Chris
well.... i know the OUT OF MOST PEOPLE method, not so me (maybe after i start working ?)
I will give it a try, but where to connect exactly ? (Refer to post 2 attachment diagram)
Or easier, any reading material (long long thing) about this method in details ? what grounding technique is this ?(so i can find research material myself ?)
I will give it a try, but where to connect exactly ? (Refer to post 2 attachment diagram)
OR another way ?
Then i assume then they are disconnect in other way, only pass through diode to the ground. (only way to escape through diode)
Or easier, any reading material (long long thing) about this method in details ? what grounding technique is this ?(so i can find research material myself ?)
To assess signal ground and power ground, think of your circuit in terms of current. a transformer centre tap is usually where power supply ground is connected and lots is happening in terms of voltage and current, whereas a signal input is low in current.
The use of a bridge rectifier is a solution to difficult grounding issues that will not otherwise be satisfied by star earthing. Well designed amplifier boards usually consider star earthing in their layout.
You appear to have come across a difficult circuit layout, and what I have suggested with a bridge rectifier can very easily solve improper layout.
If you are concerned about noise a massive subject of its own, an emitter follower transistor power supply will greatly assist. On a heatsink arrange the collector of a MJ15003 as V+ input place a resistor of 330 ohms from the collector to the base a capacitor of 1 uf to ground and supply your amp from the emitter. This should make your amp silent in terms of noise. Diagram to follow
The use of a bridge rectifier is a solution to difficult grounding issues that will not otherwise be satisfied by star earthing. Well designed amplifier boards usually consider star earthing in their layout.
You appear to have come across a difficult circuit layout, and what I have suggested with a bridge rectifier can very easily solve improper layout.
If you are concerned about noise a massive subject of its own, an emitter follower transistor power supply will greatly assist. On a heatsink arrange the collector of a MJ15003 as V+ input place a resistor of 330 ohms from the collector to the base a capacitor of 1 uf to ground and supply your amp from the emitter. This should make your amp silent in terms of noise. Diagram to follow
Too complicated
This is a simple capacitance multiplier .The capacitance of 1uf is multiplied by the transistor's current gain (β). A 100uf capacitor across the load would do the same job with just 1 part.
This is a simple capacitance multiplier .The capacitance of 1uf is multiplied by the transistor's current gain (β). A 100uf capacitor across the load would do the same job with just 1 part.
any technical what they are named ? The amp V+ just need to pass through the emitter follower transistor circuit ? and other as original ? can briefly explain how it reduce the noise and how it works ? (interested) What noise does it cancel off ?
You said need to have heatsink, how big the heat sink should be, or how hot will it be ? Does it necessary to be same heatsink as output device ? (some same temperature)
About the bridge grounding seems can return the noise too (possible return on another point), will try out all grounding after i done layout my board.
You said need to have heatsink, how big the heat sink should be, or how hot will it be ? Does it necessary to be same heatsink as output device ? (some same temperature)
About the bridge grounding seems can return the noise too (possible return on another point), will try out all grounding after i done layout my board.
An emitter follower, also known as a common collector is an amplifier of current. It typically will drop 1 volt. It involves negative feedback between its collector and emitter terminals. It will reduce ripple, and extend the bandwidth of the supply.
The amount of heat is determined by the current that is applied to the base, in this example 10.9ma as you specify a 36 volt supply is fairly light. At this current it will be mildly warm. If you have room you can put it on the same heat sink as other transistors, remembering to isolate using TO3 mounting hardware. .
The amount of heat is determined by the current that is applied to the base, in this example 10.9ma as you specify a 36 volt supply is fairly light. At this current it will be mildly warm. If you have room you can put it on the same heat sink as other transistors, remembering to isolate using TO3 mounting hardware. .
Why it will extend the bandwidth ? doesn't direct connect makes maximum bandwidth ?
I just notice that the picture you attached doesn't specified the terminal of transistor, could you tell me which is connected to V+, and which to capacitor. I assume the V+ out is emitter ?
Just to ask, should this be part of amplifier, or PSU ? (power Section)
I just notice that the picture you attached doesn't specified the terminal of transistor, could you tell me which is connected to V+, and which to capacitor. I assume the V+ out is emitter ?
Just to ask, should this be part of amplifier, or PSU ? (power Section)
Hi
Bandwidth improves because of the negative feedback, this implementation is very simple
but quite effective.
I am out with my calculations, too many things on today, the resistor value should be 2K2
which provides 16ma which is about right for a MJ15003. collector is the input which with a TO3 is its case, connect the 2K2 between there and the base and emitter is the output. For further help look up a TO3 case pin out.
Cheers / Chris
Bandwidth improves because of the negative feedback, this implementation is very simple
but quite effective.
I am out with my calculations, too many things on today, the resistor value should be 2K2
which provides 16ma which is about right for a MJ15003. collector is the input which with a TO3 is its case, connect the 2K2 between there and the base and emitter is the output. For further help look up a TO3 case pin out.
Cheers / Chris
hm... So emitter is the V+ output, collector is the V+ input, then base it connected to ground through 1uF capacitor.
In the diagram, the resistor use is 330ohm, but you say 2k2 ?
Ohh, just now i finish my PSU and tried my casually made amp (previously) without consideration of ground. (simply connect there and here, as long they conduct.Going to make better one later)
It inhibit a low volume hum, so i try to eliminate it, by using the safety ground (Main AC earth) connect to the input connector. Then it very noisy, like a old time radio talking (bee.. .beep.... zzzz) and i tried the speaker output terminal also same. Any idea why happen ?
In the diagram, the resistor use is 330ohm, but you say 2k2 ?
Ohh, just now i finish my PSU and tried my casually made amp (previously) without consideration of ground. (simply connect there and here, as long they conduct.Going to make better one later)
It inhibit a low volume hum, so i try to eliminate it, by using the safety ground (Main AC earth) connect to the input connector. Then it very noisy, like a old time radio talking (bee.. .beep.... zzzz) and i tried the speaker output terminal also same. Any idea why happen ?
Hi
Yes error in calculation of resistance 2K2 is 16ma on a 36 volt supply - use 2K2 which is good for an emitter follower using a mJ15003
You need to consider ground in any design, ignoring it or casually implementing only leads to the errors you are experiencing. go back and work out why.... you will find an error- the amp is telling you that you made a mistake, or their is design flaw. also consider that the input source may be carrying a DC error or ground fault... in which case the amplifier just amplifies that error or fault. Disconnect your source does the error stop ? ... You need to patiently fault find.
cheers / Chris
Yes error in calculation of resistance 2K2 is 16ma on a 36 volt supply - use 2K2 which is good for an emitter follower using a mJ15003
You need to consider ground in any design, ignoring it or casually implementing only leads to the errors you are experiencing. go back and work out why.... you will find an error- the amp is telling you that you made a mistake, or their is design flaw. also consider that the input source may be carrying a DC error or ground fault... in which case the amplifier just amplifies that error or fault. Disconnect your source does the error stop ? ... You need to patiently fault find.
cheers / Chris
haha, tried another computer source, then the hum is no exist (or just very little). But now i tried the safety ground to input ground again, now there is no error like last time, but the current consumption increase by alot (AC light very intense). SO i prefer disconnected.
The currently grounding of the amp is according to the circuit layout, without adding extra arrangement or component. (last time my amp has the hum noise whenever i use)
hm... i use my friend's hifi amp, there is no noise whenever the power shutoff, or input plug connect and disconnect, how to achieve that ? (kinda miracle) It was a old and great amp from PROTON. And my amp will have sound when some one in the house on/off, but not his.
The currently grounding of the amp is according to the circuit layout, without adding extra arrangement or component. (last time my amp has the hum noise whenever i use)
hm... i use my friend's hifi amp, there is no noise whenever the power shutoff, or input plug connect and disconnect, how to achieve that ? (kinda miracle) It was a old and great amp from PROTON. And my amp will have sound when some one in the house on/off, but not his.
another follow up information. difference is not the source, but the music source's electrical source.
Just now the result varies because mine is using laptop battery only, while he use Main AC.
That mean AC is the culprit ? any idea how to solve this ? (using the previous method "bridge" & "emitter follower" can solve the problem ?) going to buy the transistor tmrw.
Just now the result varies because mine is using laptop battery only, while he use Main AC.
That mean AC is the culprit ? any idea how to solve this ? (using the previous method "bridge" & "emitter follower" can solve the problem ?) going to buy the transistor tmrw.
What does it conclude ?
When batteries are charging, they draw more current from the AC supply, which can produce noise. The emitter follower transistor should make your amp silent. 2K2 is Red Red Red for a carbon 3 band 1w resistor.Remember to insulate base emitter and collector away from the metal of the heat sink. The 1uf can be a film type cap like a MKT, or if funds are tight use an electrolytic observing polarity + to the base, negative to ground and use a cap with sufficient voltage. 100v is recommended as its ESR surge rating is an important parameter, but if 100v isn't available use 63v.
Cheers / Chris
Cheers / Chris
about the noise, another computer wasn't charging battery at all (detached). So something is different. SO in conclusion we must include the safety ground into amplifier circuit or doesn't ?
i have alot of spare 2k2 resistor of 0.5W (about 7), can we use it ? (4, 2 parallel, 2 series)
Also have 2.7k 0.5W(40+) too, but mostly not used here.
Will try to get the best material available, since its not much thing and do best job.
Does this setting (2k2 ohm,etc) and component are available for any voltage item ?
i have alot of spare 2k2 resistor of 0.5W (about 7), can we use it ? (4, 2 parallel, 2 series)
Also have 2.7k 0.5W(40+) too, but mostly not used here.
Will try to get the best material available, since its not much thing and do best job.
Does this setting (2k2 ohm,etc) and component are available for any voltage item ?
Safety ground is needed, power across the 2K2 is Volts x Amps ie 36x.016 = .576 just above half a watt, so with the values you have use 4x 2k2 and make a circuit like this. Note we are adding another capacitor, as it will really reduce noise, we will locate it midway across the resistors. diagram to follow
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