Path: ...!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail From: Don Y Newsgroups: sci.electronics.design Subject: Re: iPhone battery replacement Date: Thu, 6 Jun 2024 05:34:58 -0700 Organization: A noiseless patient Spider Lines: 22 Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Injection-Date: Thu, 06 Jun 2024 14:35:32 +0200 (CEST) Injection-Info: dont-email.me; posting-host="7be623c0363dffc6819743a805623c50"; logging-data="1595054"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX18ZQ+W4m2o97sK/hFxsCdzP" User-Agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:102.0) Gecko/20100101 Thunderbird/102.2.2 Cancel-Lock: sha1:vWHGPIWvuCillmzX32MRixLRdtI= In-Reply-To: Content-Language: en-US Bytes: 2258 On 6/5/2024 8:21 PM, Bertrand Sindri wrote: >> I question how the correct dialpulse timing is detected as a >> rotary dial phone imposes a specific make-break ratio and pulse >> rate. > > Blame this on the lawyers. To avoid issues of liability, if the telephone > switch detects a pulse pattern that might plausably be interpreted as an > attempt to "dial" 911, then the phone company forwards your info on to the > 911 call center. But a dial-pulse needs to be an actual make-break of the loop, not just "line noise". Would outpulsing at, for example, 400Hz ever be considered a legitimate signal? (IIRC, dial-pulse rate was ~10Hz; are there "natural phenomena that even approach that with any sort of regularity?) And, why would the "signal" suddenly disappear and not be a regular happening? I.e., why only one visit in 30 years and not once a month? > Once the 911 call center has become involved, then the police have to handle > it as if it were a request for emergency services.