Explanations on a simple power section.
- lolbou
- Old Solderhand
It's a power section (no audio in there).
D7: reverse DC supply polarity protection.
C21: cleans any AC from DC input (more filtering)
R25-R26: voltage divider to get half the DC supply for biasing purposes.
C22: decoupling cap that filters any AC from the Vr circuit to ground.
Hope that's what you're after...
D7: reverse DC supply polarity protection.
C21: cleans any AC from DC input (more filtering)
R25-R26: voltage divider to get half the DC supply for biasing purposes.
C22: decoupling cap that filters any AC from the Vr circuit to ground.
Hope that's what you're after...
- Are you a mod or a rocker?
- Uh, no, I'm a mocker.
- Uh, no, I'm a mocker.
Information
- Posts: 3
- Joined: 29 Jun 2010, 02:13
thanks..this is what i'm after..
just few more question..
1. for D7, does it means that if the DC supply is -ve, the circuit will be short-circuited through D7?
2. for R25&R26, is there any effect if i change the resistor to another value?ie 5k for both resistor?
3. for C22, where does this AC is coming from?is it from the DC supply or the VR circuit?
just few more question..
1. for D7, does it means that if the DC supply is -ve, the circuit will be short-circuited through D7?
2. for R25&R26, is there any effect if i change the resistor to another value?ie 5k for both resistor?
3. for C22, where does this AC is coming from?is it from the DC supply or the VR circuit?
- lolbou
- Old Solderhand
Spot on! Imagine you plug the wrong adapter with positive voltage inside the plug and negative outside the plug (the opposite from the Boss-PSA ones), then D7 shorts to prevent any further damage.rockerpaluza wrote:1. for D7, does it means that if the DC supply is -ve, the circuit will be short-circuited through D7?
You'll get the same Vr with two 5k resistors. See these at GEO and analog.com for further tips. You need to consider your current draw and supply type (battery or wall-wart).rockerpaluza wrote:2. for R25&R26, is there any effect if i change the resistor to another value?ie 5k for both resistor?
It comes from the opamp's power supply itself (there's an AC current draw because of its AC activity).rockerpaluza wrote:3. for C22, where does this AC is coming from?is it from the DC supply or the VR circuit?
- Are you a mod or a rocker?
- Uh, no, I'm a mocker.
- Uh, no, I'm a mocker.
Information
- Posts: 3
- Joined: 29 Jun 2010, 02:13
for C22,do you mean the op-amp is coming from external circuit(VR node)?