HELLO all
I have an old Philips make cassette tape recorder model no. RR899 Which has a 150 Watts pmpo power. Upon opening the case I found it has two numbers of TA8227P ICs whose data sheet shows that it's a dual 2.5 Watts chip. So obviously the chips have been bridged to get two stereo channels by Philips company. So my question is -
1. How a 5 + 5 watts (10 watts ) chilps can peak to 150 Watts as claimed by the company?
2. How to bridge TA8227P IC ?
I have an old Philips make cassette tape recorder model no. RR899 Which has a 150 Watts pmpo power. Upon opening the case I found it has two numbers of TA8227P ICs whose data sheet shows that it's a dual 2.5 Watts chip. So obviously the chips have been bridged to get two stereo channels by Philips company. So my question is -
1. How a 5 + 5 watts (10 watts ) chilps can peak to 150 Watts as claimed by the company?
2. How to bridge TA8227P IC ?
Such claims of power output were common in the 1980's and 90's. A modest amp of a few watts rms could claim to have a total peak music power of over 100 watts. When you looked in detail this was translated as some absolute peak voltage or current the amp could deliver for a microscopic period of time and into some extremely low load impedance. Multiply that by two for stereo... you get the idea 😉
Bridging any amp involves connecting the load between the two amplifier outputs and feeding one of the amps with a phase inverted signal. The load 'floats' between these outputs and as one output goes 'up' in voltage the other goes 'down' by the same amount. The result is the load sees twice the voltage swing as a non bridged amp.
You have to ensure that when bridged, each amp does not exceed its limits.
Bridging any amp involves connecting the load between the two amplifier outputs and feeding one of the amps with a phase inverted signal. The load 'floats' between these outputs and as one output goes 'up' in voltage the other goes 'down' by the same amount. The result is the load sees twice the voltage swing as a non bridged amp.
You have to ensure that when bridged, each amp does not exceed its limits.
From WikiPedia:
PMPO, which stands for Peak Music Power Output[22][23] or Peak momentary performance output,[24] is a much more dubious figure of merit, of interest more to advertising copy-writers than to consumers.[25] The term PMPO has never been defined in any standard,[26] but it is often taken to be the sum of some sort of peak power for each amplifier in a system. Different manufacturers use different definitions, so that the ratio of PMPO to continuous power output varies widely; it is not possible to convert from one to the other. Most amplifiers can sustain their PMPO for only a very short time, if at all; loudspeakers are not designed to withstand their stated PMPO for anything but a momentary peak without serious damage.
With 20V supply and 2.5A peak (absolute maximum ratings) I can't make the 150W PMPO relate to real Watts in any sense.
Bridging a TA8227 is simple: Take an input signal and invert it. Send the non-inverted signal to one input and the inverted signal to the other input. Then you have a bridged output.
PMPO, which stands for Peak Music Power Output[22][23] or Peak momentary performance output,[24] is a much more dubious figure of merit, of interest more to advertising copy-writers than to consumers.[25] The term PMPO has never been defined in any standard,[26] but it is often taken to be the sum of some sort of peak power for each amplifier in a system. Different manufacturers use different definitions, so that the ratio of PMPO to continuous power output varies widely; it is not possible to convert from one to the other. Most amplifiers can sustain their PMPO for only a very short time, if at all; loudspeakers are not designed to withstand their stated PMPO for anything but a momentary peak without serious damage.
With 20V supply and 2.5A peak (absolute maximum ratings) I can't make the 150W PMPO relate to real Watts in any sense.
Bridging a TA8227 is simple: Take an input signal and invert it. Send the non-inverted signal to one input and the inverted signal to the other input. Then you have a bridged output.
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