posted to FB group Vintage Transistor Radios today.<\/p>\n
I got tired of spending a lot of money on new 9 volt batteries, so I built a dc-to-dc converter, that takes two AA or AAA batteries and converts 3 volts to 9 volts DC. One problem is that I got it to put out about 10 milliamps or 90 milliwatts, so it’s not powerful enough to run a 9 volt radio. But it works great for digital multimeters and other small test equipment. The converter fits where the 9V battery goes, so I had to put the battery holder on the outside of the case.<\/p>\n
These have cut down my costs for 9V alkalines. But the converter draws some current when the meter is off, so it needs its own on\/off switch. Another solution to low current 9V battery is to use three CR2032 coin cells in series. This gives 9V at a few milliamps, and will fit inside of the battery compartment. It’s not for long term use. I had some CR123 cells, so I connected three in series, and these can power a radio, which might take 20 to 30 milliamps. But CR123 cells are expensive.<\/p>\n
One thing I’ve noticed is that I’ve never seen an alkaline button cell leak. 👍<\/p>\n","protected":false},"excerpt":{"rendered":"
posted to FB group Vintage Transistor Radios today. I got tired of spending a lot of money on new 9 volt batteries, so I built a dc-to-dc converter, that takes two AA or AAA batteries and converts 3 volts to 9 volts DC. One problem is that I got it to put out about 10 <\/p>\n (Read More…)<\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-12469","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/12469","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=12469"}],"version-history":[{"count":1,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/12469\/revisions"}],"predecessor-version":[{"id":12470,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/12469\/revisions\/12470"}],"wp:attachment":[{"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=12469"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=12469"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/rustybolt.info\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=12469"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}