A Simple, Accurate Audio Method of Battery Condition Measurement

Hoag YM. A Simple, Accurate Audio Method of Battery Condition Measurement. In: AES Convention 17. Audio Engineering Society; 1965. Paper 407. Available from: https://aes.org/publications/elibrary-page/?id=1033

@inproceedings{Hoag1965_1033,
  author = {Hoag, Yates M.},
  title = {{A Simple, Accurate Audio Method of Battery Condition Measurement}},
  booktitle = {AES Convention 17},
  note = {Paper 407},
  year = {1965},
  month = oct,
  publisher = {Audio Engineering Society},
  url = {https://aes.org/publications/elibrary-page/?id=1033}
}

TY  - CPAPER
TI  - A Simple, Accurate Audio Method of Battery Condition Measurement
AU  - Hoag, Yates M.
T2  - AES Convention 17
M1  - Paper 407
PY  - 1965
DA  - 1965/10/06
UR  - https://aes.org/publications/elibrary-page/?id=1033
PB  - Audio Engineering Society
LA  - en
AB  - A low cost audio oscillator method of indicating battery condition in small pocket radios and the like where a meter is prohibited by cost and space considerations. In use, a button is pressed and if a -beep- is heard from the speaker, this indicates battery condition is good. If there is no -beep-, or if it is very weak, the listener knows he should soon replace the battery, even though performance of the set seems OK to him. The impedance value for the feedback circuit is chosen to yield oscillation failure at some desired point in the battery voltage curve appropriate to the circuit and transistor betas.
ER  -